diff --git a/res/values-b+sr+Latn/strings.xml b/res/values-b+sr+Latn/strings.xml
index c9e8f4c..4b4c9c2 100644
--- a/res/values-b+sr+Latn/strings.xml
+++ b/res/values-b+sr+Latn/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Treba da restartujte uređaj da biste promenili ovo podešavanje."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Restartuj"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Otkaži"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Podesi prenosivi eSIM kao podrazumevani"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Napajanje za radio na mobilnim uređajima"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Prikaži adresar SIM-a"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Prikaži brojeve za fiksno biranje"</string>
diff --git a/res/values-bn/strings.xml b/res/values-bn/strings.xml
index 1605181..952a5a8 100644
--- a/res/values-bn/strings.xml
+++ b/res/values-bn/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"এই সেটিং পরিবর্তন করতে আপনার ডিভাইস রিস্টার্ট করতে হবে।"</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"রিস্টার্ট করুন"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"বাদ দিন"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"সরিয়ে দেওয়া যায় এমন eSIM ডিফল্ট হিসেবে সেট করুন"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"মোবাইল রেডিওর গুণমান"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"সিম অ্যাড্রেস বুক দেখুন"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"স্থায়ী ডায়াল নম্বরগুলি দেখুন"</string>
diff --git a/res/values-cs/strings.xml b/res/values-cs/strings.xml
index 590f311..2e07e42 100644
--- a/res/values-cs/strings.xml
+++ b/res/values-cs/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Ke změně nastavení je nutné restartovat zařízení."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Restartovat"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Zrušit"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Nastavit vyjímatelnou eSIM jako výchozí"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Výkon mobilního přijímače"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Zobrazit adresář SIM karty"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Zobrazit povolená telefonní čísla"</string>
diff --git a/res/values-es-rUS/strings.xml b/res/values-es-rUS/strings.xml
index d12f9c0..f681ae3 100644
--- a/res/values-es-rUS/strings.xml
+++ b/res/values-es-rUS/strings.xml
@@ -115,7 +115,7 @@
     <string name="sum_cfb_disabled" msgid="3589913334164866035">"Desactivado"</string>
     <string name="disable_cfb_forbidden" msgid="4831494744351633961">"Tu proveedor no admite la inhabilitación del desvío de llamadas cuando tu teléfono está ocupado."</string>
     <string name="labelCFNRy" msgid="3403533792248457946">"Cuando no haya respuesta"</string>
-    <string name="messageCFNRy" msgid="7644434155765359009">"Número cuando no hay respuesta"</string>
+    <string name="messageCFNRy" msgid="7644434155765359009">"Número cuando no contesta"</string>
     <string name="sum_cfnry_enabled" msgid="3000500837493854799">"Reenviar a <xliff:g id="PHONENUMBER">{0}</xliff:g>"</string>
     <string name="sum_cfnry_disabled" msgid="1990563512406017880">"Desactivado"</string>
     <string name="disable_cfnry_forbidden" msgid="3174731413216550689">"Tu proveedor no admite la inhabilitación del desvío de llamadas cuando tu teléfono no responde."</string>
diff --git a/res/values-fa/strings.xml b/res/values-fa/strings.xml
index 948ace7..d76c2ab 100644
--- a/res/values-fa/strings.xml
+++ b/res/values-fa/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"برای تغییر این تنظیم، باید دستگاه را بازراه‌اندازی کنید."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"بازراه‌اندازی"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"لغو"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"تنظیم سیم‌کارت داخلی جداشدنی به‌عنوان پیش‌فرض"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"توان رادیوی تلفن همراه"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"مشاهده دفترچه نشانی سیم‌کارت"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"مشاهده شماره‌های شماره‌گیری ثابت"</string>
diff --git a/res/values-fr/strings.xml b/res/values-fr/strings.xml
index 901c032..05bbb5d 100644
--- a/res/values-fr/strings.xml
+++ b/res/values-fr/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Vous devez redémarrer l\'appareil pour modifier ce paramètre."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Redémarrer"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Annuler"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Définir l\'eSIM amovible comme SIM par défaut"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Alimentation radio mobile"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Afficher le carnet d\'adresses de la carte SIM"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Afficher les numéros autorisés"</string>
diff --git a/res/values-hi/strings.xml b/res/values-hi/strings.xml
index 255063c..6b358e5 100644
--- a/res/values-hi/strings.xml
+++ b/res/values-hi/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"इस सेटिंग को बदलने के लिए आपको अपना डिवाइस रीस्टार्ट करना होगा."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"रीस्टार्ट करें"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"रद्द करें"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"हटाए जा सकने वाले ई-सिम को डिफ़ॉल्ट के तौर पर सेट करें"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"मोबाइल रेडियो पावर"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"सिम में संपर्कों के पते की सूची देखें"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"फ़िक्स्ड डायलिंग नंबर देखें"</string>
diff --git a/res/values-it/strings.xml b/res/values-it/strings.xml
index e11daad..7e06e53 100644
--- a/res/values-it/strings.xml
+++ b/res/values-it/strings.xml
@@ -572,7 +572,7 @@
     <string name="pin_puk_system_user_only" msgid="1045147220686867922">"Solo il proprietario del dispositivo può inserire i codici PIN/PUK."</string>
     <string name="police_type_description" msgid="2819533883972081757">"Polizia"</string>
     <string name="ambulance_type_description" msgid="6798237503553180461">"Ambulanza"</string>
-    <string name="fire_type_description" msgid="6565200468934914930">"Pompieri"</string>
+    <string name="fire_type_description" msgid="6565200468934914930">"Vigili del fuoco"</string>
     <string name="description_concat_format" msgid="2014471565101724088">"%1$s, %2$s"</string>
     <string name="dialerKeyboardHintText" msgid="1115266533703764049">"Usa tastiera"</string>
     <string name="onscreenHoldText" msgid="4025348842151665191">"In attesa"</string>
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Riavvia il dispositivo per modificare questa impostazione."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Riavvia"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Annulla"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Imposta la eSIM rimovibile come predefinita"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Potenza del segnale radio mobile"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Visualizza rubrica SIM"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Visualizza numeri consentiti"</string>
diff --git a/res/values-lv/strings.xml b/res/values-lv/strings.xml
index d012da9..992ba43 100644
--- a/res/values-lv/strings.xml
+++ b/res/values-lv/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Lai mainītu šo iestatījumu, jums jārestartē ierīce."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Restartēt"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Atcelt"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Iestatīt noņemamu eSIM kā noklusējumu"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Mobilā tālruņa radio signāla stiprums"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Skatīt SIM adrešu grāmatu"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Skatīt ierobežotā zvanu saraksta numurus"</string>
diff --git a/res/values-my/strings.xml b/res/values-my/strings.xml
index a594626..ed57d75 100644
--- a/res/values-my/strings.xml
+++ b/res/values-my/strings.xml
@@ -631,7 +631,7 @@
     <string name="ota_spc_failure" msgid="904092035241370080">"အလွန်အကျွံ SPC မအောင်မြင်မှုများ"</string>
     <string name="ota_call_end" msgid="8657746378290737034">"နောက်သို့"</string>
     <string name="ota_try_again" msgid="6914781945599998550">"ပြန်ကြိုးစားပါ"</string>
-    <string name="ota_next" msgid="2041016619313475914">"ရှေ့သို့"</string>
+    <string name="ota_next" msgid="2041016619313475914">"ရှေ့ဆက်သွားရန်"</string>
     <string name="ecm_exit_dialog" msgid="4200691880721429078">"EcmExitDialog"</string>
     <string name="phone_entered_ecm_text" msgid="8431238297843035842">"အရေးပေါ်ပြန်လည်ခေါ်ဆိုမှုအား ရိုက်သွင်းပြီး"</string>
     <string name="phone_in_ecm_notification_title" msgid="6825016389926367946">"အရေးပေါ်ပြန်လည်ခေါ်ဆိုမှု"</string>
diff --git a/res/values-pt/strings.xml b/res/values-pt/strings.xml
index ab6d5d5..3099786 100644
--- a/res/values-pt/strings.xml
+++ b/res/values-pt/strings.xml
@@ -595,7 +595,7 @@
     <string name="hac_mode_title" msgid="4127986689621125468">"Aparelhos auditivos"</string>
     <string name="hac_mode_summary" msgid="7774989500136009881">"Ativar compatibilidade com aparelhos auditivos"</string>
     <string name="rtt_mode_title" msgid="3075948111362818043">"Chamada com mensagem de texto em tempo real (RTT)"</string>
-    <string name="rtt_mode_summary" msgid="8631541375609989562">"Permitir o envio de mensagens de texto em uma ligação"</string>
+    <string name="rtt_mode_summary" msgid="8631541375609989562">"Permitir o envio de mensagens de texto em uma chamada de voz"</string>
     <string name="rtt_mode_more_information" msgid="587500128658756318">"A RTT ajuda os autores das chamadas com deficiências como surdez, dificuldade de audição ou fala ou que precisam de outros recursos além de voz.&lt;br&gt; &lt;a href=<xliff:g id="URL">http://support.google.com/mobile?p=telephony_rtt</xliff:g>&gt;Saiba mais&lt;/a&gt;\n       &lt;br&gt;&lt;br&gt; — As chamadas RTT são salvas como transcrições de mensagem\n       &lt;br&gt; — A RTT não está disponível para videochamadas"</string>
     <string name="no_rtt_when_roaming" msgid="5268008247378355389">"Observação: a RTT não está disponível em roaming"</string>
   <string-array name="tty_mode_entries">
@@ -655,7 +655,7 @@
     <string name="contactPhoto" msgid="7885089213135154834">"foto do contato"</string>
     <string name="goPrivate" msgid="4645108311382209551">"conversar em particular"</string>
     <string name="selectContact" msgid="1527612842599767382">"selecionar contato"</string>
-    <string name="not_voice_capable" msgid="2819996734252084253">"Ligação não compatível"</string>
+    <string name="not_voice_capable" msgid="2819996734252084253">"Chamada de voz não compatível"</string>
     <string name="description_dial_button" msgid="8614631902795087259">"discar"</string>
     <string name="description_dialpad_button" msgid="7395114120463883623">"Mostrar teclado"</string>
     <string name="pane_title_emergency_dialpad" msgid="3627372514638694401">"Teclado de emergência"</string>
@@ -815,7 +815,7 @@
     <string name="supp_service_held_call_released" msgid="2847835124639112410">"A chamada em espera foi desconectada."</string>
     <string name="callFailed_otasp_provisioning_in_process" msgid="3345666183602879326">"Não é possível ligar porque o dispositivo está sendo provisionado no momento,"</string>
     <string name="callFailed_already_dialing" msgid="7250591188960691086">"Não é possível ligar porque há outra chamada sendo realizada."</string>
-    <string name="callFailed_already_ringing" msgid="2376603543544289303">"Não é possível ligar porque há uma ligação recebida que não foi atendida. Atenda ou rejeite essa chamada antes de fazer outra."</string>
+    <string name="callFailed_already_ringing" msgid="2376603543544289303">"Não é possível ligar porque há uma chamada recebida que não foi atendida. Atenda ou rejeite essa chamada antes de fazer outra."</string>
     <string name="callFailed_calling_disabled" msgid="5010992739401206283">"Não é possível ligar porque as chamadas foram desativadas pela propriedade \"ro.telephony.disable-call system\"."</string>
     <string name="callFailed_too_many_calls" msgid="2761754044990799580">"Não é possível ligar porque já há duas chamadas em andamento. Encerre uma das chamadas ou mescle-as em uma conferência antes de fazer outra."</string>
     <string name="supp_service_over_ut_precautions" msgid="2145018231396701311">"Verifique se os dados móveis estão ativados para usar este serviço: <xliff:g id="SUPP_SERVICE">%s</xliff:g>. Você pode alterar essa opção nas configurações da rede móvel."</string>
@@ -883,7 +883,7 @@
     <string name="radio_info_ppp_received_label" msgid="5753592451640644889">"Dados recebidos:"</string>
     <string name="radio_info_gsm_service_label" msgid="6443348321714241328">"Serviço de voz:"</string>
     <string name="radio_info_signal_strength_label" msgid="5545444702102543260">"Potência do sinal:"</string>
-    <string name="radio_info_call_status_label" msgid="7693575431923095487">"Status da ligação:"</string>
+    <string name="radio_info_call_status_label" msgid="7693575431923095487">"Status da chamada de voz:"</string>
     <string name="radio_info_ppp_sent_label" msgid="6542208429356199695">"Dados enviados:"</string>
     <string name="radio_info_message_waiting_label" msgid="1886549432566952078">"Mensagem em espera:"</string>
     <string name="radio_info_phone_number_label" msgid="2533852539562512203">"Número de telefone:"</string>
diff --git a/res/values-sr/strings.xml b/res/values-sr/strings.xml
index 5a494ec..83c9106 100644
--- a/res/values-sr/strings.xml
+++ b/res/values-sr/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Треба да рестартујте уређај да бисте променили ово подешавање."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Рестартуј"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Откажи"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Подеси преносиви eSIM као подразумевани"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Напајање за радио на мобилним уређајима"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Прикажи адресар SIM-а"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Прикажи бројеве за фиксно бирање"</string>
diff --git a/res/values-sw/strings.xml b/res/values-sw/strings.xml
index 202381f..0c45bb5 100644
--- a/res/values-sw/strings.xml
+++ b/res/values-sw/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Unahitaji kuzima kifaa chako na ukiwashe tena ili ubadilishe mipangilio hii."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"Zima kisha uwashe"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Ghairi"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Weka eSIM Inayoweza Kuondolewa kama Chaguomsingi"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Nishati ya Redio ya Vifaa vya Mkononi"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Angalia Kitabu cha Anwani katika SIM"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Ona Nambari za Simu Zilizobainishwa"</string>
diff --git a/res/values-te/strings.xml b/res/values-te/strings.xml
index b022cf8..37d1f82 100644
--- a/res/values-te/strings.xml
+++ b/res/values-te/strings.xml
@@ -618,7 +618,7 @@
     <string name="ota_hfa_activation_dialog_message" msgid="7921718445773342996">"ఫోన్ మీ మొబైల్ డేటా సేవను సక్రియం చేస్తోంది.\n\nదీనికి గరిష్టంగా 5 నిమిషాలు పట్టవచ్చు."</string>
     <string name="ota_skip_activation_dialog_title" msgid="7666611236789203797">"సక్రియం చేయడాన్ని దాటవేయాలా?"</string>
     <string name="ota_skip_activation_dialog_message" msgid="6691722887019708713">"మీరు సక్రియం చేయడాన్ని దాటవేస్తే, కాల్స్‌ చేయలేరు లేదా మొబైల్ డేటా నెట్‌వర్క్‌లకు కనెక్ట్ చేయలేరు (మీరు Wi-Fi నెట్‌వర్క్‌లకు కనెక్ట్ చేయగలిగినప్పటికీ). మీరు మీ ఫోన్‌ను సక్రియం చేసేవరకు, దాన్ని ప్రారంభించే ప్రతిసారీ సక్రియం చేయమని మిమ్మల్ని అడుగుతుంది."</string>
-    <string name="ota_skip_activation_dialog_skip_label" msgid="5908029466817825633">"స్కిప్ చేయండి"</string>
+    <string name="ota_skip_activation_dialog_skip_label" msgid="5908029466817825633">"దాటవేయి"</string>
     <string name="ota_activate" msgid="7939695753665438357">"యాక్టివేట్ చేయండి"</string>
     <string name="ota_title_activate_success" msgid="1272135024761004889">"ఫోన్ సక్రియం చేయబడింది."</string>
     <string name="ota_title_problem_with_activation" msgid="7019745985413368726">"సక్రియం చేయడంలో సమస్య"</string>
diff --git a/res/values-tl/strings.xml b/res/values-tl/strings.xml
index 6ec3320..633c53e 100644
--- a/res/values-tl/strings.xml
+++ b/res/values-tl/strings.xml
@@ -835,7 +835,8 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"Kailangan mong i-restart ang device para mabago ang setting."</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"I-restart"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"Kanselahin"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"Itakda na Default ang Naaalis na eSIM"</string>
+    <!-- no translation found for removable_esim_string (7931369811671787649) -->
+    <skip />
     <string name="radio_info_radio_power" msgid="8805595022160471587">"Mobile Radio Power"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"Tingnan ang Address Book ng SIM"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"Tingnan ang Mga Fixed Dialing Number"</string>
diff --git a/res/values-zh-rHK/strings.xml b/res/values-zh-rHK/strings.xml
index 213ade9..2470a47 100644
--- a/res/values-zh-rHK/strings.xml
+++ b/res/values-zh-rHK/strings.xml
@@ -835,7 +835,7 @@
     <string name="dsds_dialog_message" msgid="4047480385678538850">"您需要重新啟動裝置，才可變更此設定。"</string>
     <string name="dsds_dialog_confirm" msgid="9032004888134129885">"重新啟動"</string>
     <string name="dsds_dialog_cancel" msgid="3245958947099586655">"取消"</string>
-    <string name="removable_esim_string" msgid="7931369811671787649">"將可移除的 eSIM 卡設為預設值"</string>
+    <string name="removable_esim_string" msgid="7931369811671787649">"將可移除的 eSIM 卡設為預設 eSIM 卡"</string>
     <string name="radio_info_radio_power" msgid="8805595022160471587">"流動無線電的電源"</string>
     <string name="radioInfo_menu_viewADN" msgid="4533179730908559846">"查看 SIM 卡通訊錄"</string>
     <string name="radioInfo_menu_viewFDN" msgid="1847236480527032061">"查看固定撥號"</string>
diff --git a/src/com/android/phone/CarrierConfigLoader.java b/src/com/android/phone/CarrierConfigLoader.java
index 307170a..cb774c7 100644
--- a/src/com/android/phone/CarrierConfigLoader.java
+++ b/src/com/android/phone/CarrierConfigLoader.java
@@ -1321,7 +1321,6 @@
             boolean persistent) {
         mContext.enforceCallingOrSelfPermission(
                 android.Manifest.permission.MODIFY_PHONE_STATE, null);
-        //TODO: Also check for SHELL UID to restrict this method to testing only (b/131326259)
         int phoneId = SubscriptionManager.getPhoneId(subscriptionId);
         if (!SubscriptionManager.isValidPhoneId(phoneId)) {
             logd("Ignore invalid phoneId: " + phoneId + " for subId: " + subscriptionId);
diff --git a/src/com/android/phone/ImsRcsController.java b/src/com/android/phone/ImsRcsController.java
index bf55764..d4a0f1e 100644
--- a/src/com/android/phone/ImsRcsController.java
+++ b/src/com/android/phone/ImsRcsController.java
@@ -252,7 +252,7 @@
         } catch (ImsException e) {
             Log.e(TAG, "isCapable: sudId=" + subId
                     + ", capability=" + capability + ", " + e.getMessage());
-            return false;
+            throw new ServiceSpecificException(e.getCode(), e.getMessage());
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -278,7 +278,7 @@
         } catch (ImsException e) {
             Log.e(TAG, "isAvailable: sudId=" + subId
                     + ", capability=" + capability + ", " + e.getMessage());
-            return false;
+            throw new ServiceSpecificException(e.getCode(), e.getMessage());
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -786,16 +786,43 @@
         int slotId = phone.getPhoneId();
         if (!skipVerifyingConfig) {
             verifyImsRcsConfiguredOrThrow(slotId);
+            verifyRcsSubIdActiveOrThrow(slotId, subId);
         }
         RcsFeatureController c = mRcsService.getFeatureController(slotId);
         if (c == null) {
+            // If we hit this case, we have verified that TelephonyRcsService has processed any
+            // subId changes for the associated slot and applied configs. In this case, the configs
+            // do not have the RCS feature enabled.
             throw new ServiceSpecificException(ImsException.CODE_ERROR_UNSUPPORTED_OPERATION,
                     "The requested operation is not supported for subId " + subId);
         }
+        if (!skipVerifyingConfig && c.getAssociatedSubId() != subId) {
+            // If we hit this case, the ImsFeature has not finished setting up the RCS feature yet
+            // or the RCS feature has crashed and is being set up again.
+            Log.w(TAG, "getRcsFeatureController: service unavailable on slot " + slotId
+                    + " for subId " + subId);
+            throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE,
+                    "The ImsService is not currently available for subid " + subId
+                            + ", please try again");
+        }
         return c;
     }
 
     /**
+     * Ensure the TelephonyRcsService is tracking the supplied subId for the supplied slotId and has
+     * set up the stack.
+     */
+    private void verifyRcsSubIdActiveOrThrow(int slotId, int subId) {
+        if (mRcsService.verifyActiveSubId(slotId, subId)) return;
+
+        Log.w(TAG, "verifyRcsSubIdActiveOrThrow: verify failed, service not set up yet on "
+                + "slot " + slotId + " for subId " + subId);
+        throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE,
+                "ImsService set up in progress for subId " + subId
+                        + ", please try again");
+    }
+
+    /**
      * Throw an ImsException if the IMS resolver does not have an ImsService configured for RCS
      * for the given slot ID or no ImsResolver instance has been created.
      * @param slotId The slot ID that the IMS service is created for.
diff --git a/src/com/android/services/telephony/TelephonyConnection.java b/src/com/android/services/telephony/TelephonyConnection.java
index ed07726..684e03a 100644
--- a/src/com/android/services/telephony/TelephonyConnection.java
+++ b/src/com/android/services/telephony/TelephonyConnection.java
@@ -2016,32 +2016,47 @@
     }
 
     @VisibleForTesting
-    public PersistableBundle getCarrierConfig() {
+    public @NonNull PersistableBundle getCarrierConfig() {
         Phone phone = getPhone();
         if (phone == null) {
-            return null;
+            Log.w(this,
+                    "getCarrierConfig: phone is null. Returning CarrierConfigManager"
+                            + ".getDefaultConfig()");
+            return CarrierConfigManager.getDefaultConfig();
         }
-        return PhoneGlobals.getInstance().getCarrierConfigForSubId(phone.getSubId());
+
+        // potential null returned from .getCarrierConfigForSubId() and method guarantees non-null.
+        // hence, need for try/finally block
+        PersistableBundle pb = null;
+        try {
+            pb = PhoneGlobals.getInstance().getCarrierConfigForSubId(phone.getSubId());
+        } catch (Exception e) {
+            Log.e(this, e,
+                    "getCarrierConfig: caught Exception when calling "
+                            + "PhoneGlobals.getCarrierConfigForSubId(phone.getSubId()). Returning "
+                            + "CarrierConfigManager.getDefaultConfig()");
+        } finally {
+            if (pb == null) {
+                pb = CarrierConfigManager.getDefaultConfig();
+            }
+        }
+        return pb;
+    }
+
+    @VisibleForTesting
+    public boolean isRttMergeSupported(@NonNull PersistableBundle pb) {
+        return pb.getBoolean(CarrierConfigManager.KEY_ALLOW_MERGING_RTT_CALLS_BOOL);
     }
 
     private boolean canDeflectImsCalls() {
-        PersistableBundle b = getCarrierConfig();
-        // Return false if the CarrierConfig is unavailable
-        if (b != null) {
-            return b.getBoolean(
-                    CarrierConfigManager.KEY_CARRIER_ALLOW_DEFLECT_IMS_CALL_BOOL) &&
-                    isValidRingingCall();
-        }
-        return false;
+        return getCarrierConfig().getBoolean(
+                CarrierConfigManager.KEY_CARRIER_ALLOW_DEFLECT_IMS_CALL_BOOL)
+                && isValidRingingCall();
     }
 
     private boolean isCallTransferSupported() {
-        PersistableBundle b = getCarrierConfig();
-        // Return false if the CarrierConfig is unavailable
-        if (b != null) {
-            return b.getBoolean(CarrierConfigManager.KEY_CARRIER_ALLOW_TRANSFER_IMS_CALL_BOOL);
-        }
-        return false;
+        return getCarrierConfig().getBoolean(
+                CarrierConfigManager.KEY_CARRIER_ALLOW_TRANSFER_IMS_CALL_BOOL);
     }
 
     private boolean canTransfer(TelephonyConnection c) {
@@ -3038,8 +3053,6 @@
         if (isIms) {
             isVoWifiEnabled = isWfcEnabled(phone);
         }
-        boolean isRttMergeSupported = getCarrierConfig()
-                .getBoolean(CarrierConfigManager.KEY_ALLOW_MERGING_RTT_CALLS_BOOL);
         PhoneAccountHandle phoneAccountHandle = isIms ? PhoneUtils
                 .makePstnPhoneAccountHandle(phone.getDefaultPhone())
                 : PhoneUtils.makePstnPhoneAccountHandle(phone);
@@ -3077,7 +3090,7 @@
         if (mTreatAsEmergencyCall) {
             isConferenceSupported = false;
             Log.d(this, "refreshConferenceSupported = false; emergency call");
-        } else if (isRtt() && !isRttMergeSupported) {
+        } else if (isRtt() && !isRttMergeSupported(getCarrierConfig())) {
             isConferenceSupported = false;
             Log.d(this, "refreshConferenceSupported = false; rtt call");
         } else if (!isConferencingSupported || isIms && !isImsConferencingSupported) {
@@ -3134,12 +3147,9 @@
         Phone phone = getPhone();
         if (phone != null && (phone.getPhoneType() == TelephonyManager.PHONE_TYPE_CDMA)
                 && !mOriginalConnection.isIncoming()) {
-            PersistableBundle pb = getCarrierConfig();
-            if (pb != null) {
-                showOrigDialString = pb.getBoolean(CarrierConfigManager
-                        .KEY_CONFIG_SHOW_ORIG_DIAL_STRING_FOR_CDMA_BOOL);
-                Log.d(this, "showOrigDialString: " + showOrigDialString);
-            }
+            showOrigDialString = getCarrierConfig().getBoolean(CarrierConfigManager
+                    .KEY_CONFIG_SHOW_ORIG_DIAL_STRING_FOR_CDMA_BOOL);
+            Log.d(this, "showOrigDialString: " + showOrigDialString);
         }
         return showOrigDialString;
     }
@@ -3716,8 +3726,7 @@
         if (mOriginalConnection.isIncoming()
                 && !TextUtils.isEmpty(mOriginalConnection.getAddress())
                 && mOriginalConnection.getAddress().startsWith(JAPAN_COUNTRY_CODE_WITH_PLUS_SIGN)) {
-            PersistableBundle b = getCarrierConfig();
-            return b != null && b.getBoolean(
+            return getCarrierConfig().getBoolean(
                     CarrierConfigManager.KEY_FORMAT_INCOMING_NUMBER_TO_NATIONAL_FOR_JP_BOOL);
         }
         return false;
@@ -3742,8 +3751,7 @@
      * otherwise.
      */
     private boolean supportsD2DUsingRtp() {
-        PersistableBundle b = getCarrierConfig();
-        return b != null && b.getBoolean(
+        return getCarrierConfig().getBoolean(
                 CarrierConfigManager.KEY_SUPPORTS_DEVICE_TO_DEVICE_COMMUNICATION_USING_RTP_BOOL);
     }
 
@@ -3751,8 +3759,7 @@
      * @return {@code true} if the carrier supports D2D using DTMF digits, {@code false} otherwise.
      */
     private boolean supportsD2DUsingDtmf() {
-        PersistableBundle b = getCarrierConfig();
-        return b != null && b.getBoolean(
+        return getCarrierConfig().getBoolean(
                 CarrierConfigManager.KEY_SUPPORTS_DEVICE_TO_DEVICE_COMMUNICATION_USING_DTMF_BOOL);
     }
 
@@ -3761,8 +3768,7 @@
      * extensions used in D2D comms, {@code false} otherwise.
      */
     private boolean supportsSdpNegotiationOfRtpHeaderExtensions() {
-        PersistableBundle b = getCarrierConfig();
-        return b != null && b.getBoolean(
+        return getCarrierConfig().getBoolean(
                 CarrierConfigManager
                         .KEY_SUPPORTS_SDP_NEGOTIATION_OF_D2D_RTP_HEADER_EXTENSIONS_BOOL);
     }
diff --git a/src/com/android/services/telephony/TelephonyConnectionService.java b/src/com/android/services/telephony/TelephonyConnectionService.java
index 071376d..12ebad7 100644
--- a/src/com/android/services/telephony/TelephonyConnectionService.java
+++ b/src/com/android/services/telephony/TelephonyConnectionService.java
@@ -232,6 +232,7 @@
         boolean hasIccCard(int slotId);
         boolean isCurrentEmergencyNumber(String number);
         Map<Integer, List<EmergencyNumber>> getCurrentEmergencyNumberList();
+        boolean isConcurrentCallsPossible();
     }
 
     private TelephonyManagerProxy mTelephonyManagerProxy;
@@ -271,6 +272,12 @@
                 return new HashMap<>();
             }
         }
+
+        @Override
+        public boolean isConcurrentCallsPossible() {
+            // Under DSDA, need to be determined by voice capabilities
+            return mTelephonyManager.getMaxNumberOfSimultaneouslyActiveSims() > 1;
+        }
     }
 
     /**
@@ -1636,7 +1643,13 @@
             Bundle connExtras = c.getExtras();
             Log.i(this, "retryOutgoingOriginalConnection, redialing on Phone Id: " + newPhoneToUse);
             c.clearOriginalConnection();
-            if (phoneId != newPhoneToUse.getPhoneId()) updatePhoneAccount(c, newPhoneToUse);
+            if (phoneId != newPhoneToUse.getPhoneId()) {
+                if (!mTelephonyManagerProxy.isConcurrentCallsPossible()) {
+                    disconnectAllCallsOnOtherSubs(
+                            mPhoneUtilsProxy.makePstnPhoneAccountHandle(newPhoneToUse));
+                }
+                updatePhoneAccount(c, newPhoneToUse);
+            }
             placeOutgoingConnection(c, newPhoneToUse, videoState, connExtras);
         } else {
             // We have run out of Phones to use. Disconnect the call and destroy the connection.
@@ -1834,6 +1847,9 @@
             case CallStateException.ERROR_OTASP_PROVISIONING_IN_PROCESS:
                  cause = android.telephony.DisconnectCause.OTASP_PROVISIONING_IN_PROCESS;
                  break;
+            case CallStateException.ERROR_FDN_BLOCKED:
+                 cause = android.telephony.DisconnectCause.FDN_BLOCKED;
+                 break;
         }
         connection.setTelephonyConnectionDisconnected(
                 DisconnectCauseUtil.toTelecomDisconnectCause(cause, e.getMessage(),
@@ -2645,4 +2661,23 @@
                     }
                 });
     }
+
+    private void disconnectAllCallsOnOtherSubs (@NonNull PhoneAccountHandle handle) {
+        Collection<Connection>connections = getAllConnections();
+        connections.stream()
+                .filter(c ->
+                        (c.getState() == Connection.STATE_ACTIVE
+                                || c.getState() == Connection.STATE_HOLDING)
+                                // Include any calls not on same sub as current connection.
+                                && !Objects.equals(c.getPhoneAccountHandle(), handle))
+                .forEach(c -> {
+                    if (c instanceof TelephonyConnection) {
+                        TelephonyConnection tc = (TelephonyConnection) c;
+                        Log.i(LOG_TAG, "disconnectAllCallsOnOtherSubs: disconnect" +
+                                " %s due to redial happened on other sub.",
+                                tc.getTelecomCallId());
+                        tc.hangup(android.telephony.DisconnectCause.LOCAL);
+                    }
+                });
+    }
 }
diff --git a/src/com/android/services/telephony/rcs/RcsFeatureController.java b/src/com/android/services/telephony/rcs/RcsFeatureController.java
index 0e1cb4b..48c84b1 100644
--- a/src/com/android/services/telephony/rcs/RcsFeatureController.java
+++ b/src/com/android/services/telephony/rcs/RcsFeatureController.java
@@ -19,6 +19,7 @@
 import android.annotation.AnyThread;
 import android.content.Context;
 import android.net.Uri;
+import android.telephony.SubscriptionManager;
 import android.telephony.ims.ImsException;
 import android.telephony.ims.ImsReasonInfo;
 import android.telephony.ims.aidl.IImsCapabilityCallback;
@@ -402,6 +403,17 @@
         callback.accept(mImsRcsRegistrationHelper.getImsRegistrationState());
     }
 
+    /**
+     * @return the subscription ID that is currently associated with this RCS feature.
+     */
+    public int getAssociatedSubId() {
+        RcsFeatureManager manager = getFeatureManager();
+        if (manager != null) {
+            return manager.getSubId();
+        }
+        return SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+    }
+
     private void updateCapabilities() {
         RcsFeatureManager manager = getFeatureManager();
         if (manager != null) {
diff --git a/src/com/android/services/telephony/rcs/TelephonyRcsService.java b/src/com/android/services/telephony/rcs/TelephonyRcsService.java
index dfcea74..13b3a7d 100644
--- a/src/com/android/services/telephony/rcs/TelephonyRcsService.java
+++ b/src/com/android/services/telephony/rcs/TelephonyRcsService.java
@@ -244,6 +244,22 @@
     }
 
     /**
+     * Verifies the subId supplied is the active subId for the slotId specified.
+     * If we have not processed a CARRIER_CONFIG_CHANGED indication for this subscription yet,
+     * either the subscription is not active or we have not finished setting up the feature yet.
+     * @param slotId The slotId we are verifying
+     * @param subId The subId we are verifying
+     * @return true if the subId is the active subId we are tracking for the slotId specified.
+     */
+    public boolean verifyActiveSubId(int slotId, int subId) {
+        synchronized (mLock) {
+            int currId = mSlotToAssociatedSubIds.get(slotId,
+                    SubscriptionManager.INVALID_SUBSCRIPTION_ID);
+            return subId == currId;
+        }
+    }
+
+    /**
      * ACTION_CARRIER_CONFIG_CHANGED was received by this service for a specific slot.
      * @param slotId The slotId associated with the event.
      * @param subId The subId associated with the event. May cause the subId associated with the
diff --git a/testapps/TestSliceApp/.idea/.gitignore b/testapps/TestSliceApp/.idea/.gitignore
deleted file mode 100644
index 26d3352..0000000
--- a/testapps/TestSliceApp/.idea/.gitignore
+++ /dev/null
@@ -1,3 +0,0 @@
-# Default ignored files
-/shelf/
-/workspace.xml
diff --git a/testapps/TestSliceApp/.idea/compiler.xml b/testapps/TestSliceApp/.idea/compiler.xml
deleted file mode 100644
index fb7f4a8..0000000
--- a/testapps/TestSliceApp/.idea/compiler.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <bytecodeTargetLevel target="11" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/testapps/TestSliceApp/.idea/gradle.xml b/testapps/TestSliceApp/.idea/gradle.xml
deleted file mode 100644
index 526b4c2..0000000
--- a/testapps/TestSliceApp/.idea/gradle.xml
+++ /dev/null
@@ -1,20 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="GradleMigrationSettings" migrationVersion="1" />
-  <component name="GradleSettings">
-    <option name="linkedExternalProjectsSettings">
-      <GradleProjectSettings>
-        <option name="testRunner" value="GRADLE" />
-        <option name="distributionType" value="DEFAULT_WRAPPED" />
-        <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="modules">
-          <set>
-            <option value="$PROJECT_DIR$" />
-            <option value="$PROJECT_DIR$/app" />
-          </set>
-        </option>
-        <option name="resolveModulePerSourceSet" value="false" />
-      </GradleProjectSettings>
-    </option>
-  </component>
-</project>
\ No newline at end of file
diff --git a/testapps/TestSliceApp/.idea/misc.xml b/testapps/TestSliceApp/.idea/misc.xml
deleted file mode 100644
index a329266..0000000
--- a/testapps/TestSliceApp/.idea/misc.xml
+++ /dev/null
@@ -1,76 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="DesignSurface">
-    <option name="filePathToZoomLevelMap">
-      <map>
-        <entry key="app/src/main/res/drawable/ic_launcher_background.xml" value="0.38177083333333334" />
-        <entry key="app/src/main/res/layout/_copy.xml" value="0.365625" />
-        <entry key="app/src/main/res/layout/activity_main.xml" value="0.4891304347826087" />
-        <entry key="app/src/main/res/layout/copy.xml" value="0.37135416666666665" />
-        <entry key="app/src/main/res/layout/fragment_c_b_s.xml" value="0.473731884057971" />
-        <entry key="app/src/main/res/layout/fragment_c_b_s_copy.xml" value="0.365625" />
-        <entry key="app/src/main/res/layout/fragment_main.xml" value="0.46693840579710144" />
-        <entry key="app/src/main/res/layout/fragment_prioritize_bandwidth.xml" value="0.473731884057971" />
-        <entry key="app/src/main/res/layout/fragment_prioritize_bandwidth2.xml" value="0.365625" />
-        <entry key="app/src/main/res/layout/fragment_prioritize_latency.xml" value="0.473731884057971" />
-        <entry key="app/src/main/res/layout/fragment_prioritize_latency2.xml" value="0.365625" />
-      </map>
-    </option>
-  </component>
-  <component name="NullableNotNullManager">
-    <option name="myDefaultNullable" value="androidx.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="androidx.annotation.NonNull" />
-    <option name="myNullables">
-      <value>
-        <list size="17">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
-          <item index="1" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="androidx.annotation.Nullable" />
-          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
-          <item index="5" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
-          <item index="6" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="7" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
-          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
-          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
-          <item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
-          <item index="11" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.Nullable" />
-          <item index="12" class="java.lang.String" itemvalue="io.reactivex.annotations.Nullable" />
-          <item index="13" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.Nullable" />
-          <item index="14" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
-          <item index="15" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
-          <item index="16" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
-        </list>
-      </value>
-    </option>
-    <option name="myNotNulls">
-      <value>
-        <list size="17">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
-          <item index="1" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
-          <item index="2" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
-          <item index="3" class="java.lang.String" itemvalue="androidx.annotation.NonNull" />
-          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNonNull" />
-          <item index="5" class="java.lang.String" itemvalue="com.android.annotations.NonNull" />
-          <item index="6" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
-          <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
-          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
-          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
-          <item index="10" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.NonNull" />
-          <item index="11" class="java.lang.String" itemvalue="io.reactivex.annotations.NonNull" />
-          <item index="12" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.NonNull" />
-          <item index="13" class="java.lang.String" itemvalue="lombok.NonNull" />
-          <item index="14" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
-          <item index="15" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
-          <item index="16" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
-        </list>
-      </value>
-    </option>
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="JDK" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/build/classes" />
-  </component>
-  <component name="ProjectType">
-    <option name="id" value="Android" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/testapps/TestSliceApp/.idea/vcs.xml b/testapps/TestSliceApp/.idea/vcs.xml
deleted file mode 100644
index 498ba99..0000000
--- a/testapps/TestSliceApp/.idea/vcs.xml
+++ /dev/null
@@ -1,40 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="IssueNavigationConfiguration">
-    <option name="links">
-      <list>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\bb/(\d+)(#\w+)?\b" />
-          <option name="linkRegexp" value="https://buganizer.corp.google.com/issues/$1$2" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\b(?:BUG=|FIXED=)(\d+)\b" />
-          <option name="linkRegexp" value="https://buganizer.corp.google.com/issues/$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\b(?:cl/|cr/|OCL=|DIFFBASE=|ROLLBACK_OF=)(\d+)\b" />
-          <option name="linkRegexp" value="https://critique.corp.google.com/$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\bomg/(\d+)\b" />
-          <option name="linkRegexp" value="https://omg.corp.google.com/$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\b(?:go/|goto/)([^,.&lt;&gt;()&quot;\s]+(?:[.,][^,.&lt;&gt;()&quot;\s]+)*)" />
-          <option name="linkRegexp" value="https://goto.google.com/$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="\bcs/([^\s]+[\w$])" />
-          <option name="linkRegexp" value="https://cs.corp.google.com/search/?q=$1" />
-        </IssueNavigationLink>
-        <IssueNavigationLink>
-          <option name="issueRegexp" value="(LINT\.IfChange)|(LINT\.ThenChange)" />
-          <option name="linkRegexp" value="https://goto.google.com/ifthisthenthatlint" />
-        </IssueNavigationLink>
-      </list>
-    </option>
-  </component>
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$/../.." vcs="Git" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/testapps/TestSliceApp/app/src/main/AndroidManifest.xml b/testapps/TestSliceApp/app/src/main/AndroidManifest.xml
index d28bbb0..a34c254 100644
--- a/testapps/TestSliceApp/app/src/main/AndroidManifest.xml
+++ b/testapps/TestSliceApp/app/src/main/AndroidManifest.xml
@@ -3,6 +3,8 @@
     package="com.google.android.sample.testsliceapp">
 
   <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
+  <uses-permission android:name="android.permission.MODIFY_PHONE_STATE" />
+  <uses-permission android:name="android.permission.INTERNET" />
   <application
       android:allowBackup="true"
       android:icon="@mipmap/ic_launcher"
@@ -10,7 +12,8 @@
       android:roundIcon="@mipmap/ic_launcher_round"
       android:supportsRtl="true"
       android:theme="@style/Theme.AppCompat"
-      android:versionCode="34">
+      android:versionCode="34"
+      android:usesCleartextTraffic="true">
     <activity
         android:name=".MainActivity"
         android:exported="true">
@@ -29,4 +32,4 @@
           android:value="true" />
     </service>
   </application>
-</manifest>
\ No newline at end of file
+</manifest>
diff --git a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/CBS.java b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/CBS.java
index a555ce6..c85f830 100644
--- a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/CBS.java
+++ b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/CBS.java
@@ -20,7 +20,10 @@
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
+import android.net.TelephonyNetworkSpecifier;
 import android.os.Bundle;
+import android.telephony.SubscriptionManager;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
@@ -62,6 +65,7 @@
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        mConnectivityManager = getContext().getSystemService(ConnectivityManager.class);
     }
 
     @Override
@@ -80,23 +84,33 @@
         mRelease.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                mConnectivityManager.unregisterNetworkCallback(
+                try {
+                    mConnectivityManager.unregisterNetworkCallback(
                         mProfileCheckNetworkCallback);
+                } catch (Exception e) {
+                    Log.d("SliceTest", "Exception: " + e);
+                }
             }
         });
         mRequest = view.findViewById(R.id.requestcbs);
         mRequest.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                NetworkCallback mProfileCheckNetworkCallback = new NetworkCallback() {
+                mProfileCheckNetworkCallback = new NetworkCallback() {
                     @Override
                     public void onAvailable(final Network network) {
                         mNetwork = network;
+                        Log.d("CBS", "onAvailable + " + network);
                     }
                 };
                 NetworkRequest.Builder builder = new NetworkRequest.Builder();
                 builder.addCapability(NetworkCapabilities.NET_CAPABILITY_CBS);
+                builder.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR);
+                int subId = SubscriptionManager.getDefaultDataSubscriptionId();
+                builder.setNetworkSpecifier(new TelephonyNetworkSpecifier.Builder()
+                        .setSubscriptionId(subId).build());
                 mConnectivityManager.requestNetwork(builder.build(), mProfileCheckNetworkCallback);
+                Log.d("CBS", "onClick + " + builder.build());
             }
         });
         mPing = view.findViewById(R.id.pingcbs);
@@ -106,8 +120,9 @@
                 if (mNetwork != null) {
                     //mNetwork.
                     try {
-                        new RequestTask().ping(mNetwork);
+                        new RequestTask().execute(mNetwork);
                     } catch (Exception e) {
+                        Log.d("SliceTest", "Exception: " + e);
                     }
                 }
             }
diff --git a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeBandwidth.java b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeBandwidth.java
index d997178..6812ddc 100644
--- a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeBandwidth.java
+++ b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeBandwidth.java
@@ -21,6 +21,7 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
@@ -73,6 +74,7 @@
                 new NetworkCallback() {
             @Override
             public void onAvailable(final Network network) {
+                Log.d("SliceTest", "onAvailable: " + network);
                 mNetwork = network;
             }
         };
@@ -80,23 +82,30 @@
         mRelease.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                mConnectivityManager.unregisterNetworkCallback(mProfileCheckNetworkCallback);
+                try {
+                    mConnectivityManager.unregisterNetworkCallback(
+                            mProfileCheckNetworkCallback);
+                } catch (Exception e) {
+                    Log.d("SliceTest", "Exception: " + e);
+                }
             }
         });
         mRequest = view.findViewById(R.id.requestbw);
         mRequest.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                NetworkCallback mProfileCheckNetworkCallback =
+                mProfileCheckNetworkCallback =
                         new NetworkCallback() {
                     @Override
                     public void onAvailable(final Network network) {
+                        Log.d("PrioritizeBandwidth", "onAvailable + " + network);
                         mNetwork = network;
                     }
                 };
                 NetworkRequest.Builder builder = new NetworkRequest.Builder();
                 builder.addCapability(NetworkCapabilities.NET_CAPABILITY_PRIORITIZE_BANDWIDTH);
                 mConnectivityManager.requestNetwork(builder.build(), mProfileCheckNetworkCallback);
+                Log.d("PrioritizeBandwidth", "onClick + " + builder.build());
             }
         });
         mPing = view.findViewById(R.id.pingbw);
@@ -104,10 +113,10 @@
             @Override
             public void onClick(View view) {
                 if (mNetwork != null) {
-                    //mNetwork.
                     try {
-                        new RequestTask().ping(mNetwork);
+                        new RequestTask().execute(mNetwork);
                     } catch (Exception e) {
+                        Log.d("SliceTest", "Exception: " + e);
                     }
                 }
             }
diff --git a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeLatency.java b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeLatency.java
index b45362c..45ea666 100644
--- a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeLatency.java
+++ b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/PrioritizeLatency.java
@@ -21,6 +21,7 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
@@ -61,6 +62,7 @@
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        mConnectivityManager = getContext().getSystemService(ConnectivityManager.class);
     }
 
     @Override
@@ -79,22 +81,29 @@
         mRelease.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                mConnectivityManager.unregisterNetworkCallback(mProfileCheckNetworkCallback);
+                try {
+                    mConnectivityManager.unregisterNetworkCallback(
+                            mProfileCheckNetworkCallback);
+                } catch (Exception e) {
+                    Log.d("SliceTest", "Exception: " + e);
+                }
             }
         });
         mRequest = view.findViewById(R.id.requestlatency);
         mRequest.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View view) {
-                NetworkCallback mProfileCheckNetworkCallback = new NetworkCallback() {
+                mProfileCheckNetworkCallback = new NetworkCallback() {
                     @Override
                     public void onAvailable(final Network network) {
+                        Log.d("PrioritizeLatency", "onAvailable + " + network);
                         mNetwork = network;
                     }
                 };
                 NetworkRequest.Builder builder = new NetworkRequest.Builder();
                 builder.addCapability(NetworkCapabilities.NET_CAPABILITY_PRIORITIZE_LATENCY);
                 mConnectivityManager.requestNetwork(builder.build(), mProfileCheckNetworkCallback);
+                Log.d("PrioritizeLatency", "onClick + " + builder.build());
             }
         });
         mPing = view.findViewById(R.id.pinglatency);
@@ -106,6 +115,7 @@
                     try {
                         new RequestTask().ping(mNetwork);
                     } catch (Exception e) {
+                        Log.d("SliceTest", "Exception: " + e);
                     }
                 }
             }
diff --git a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/RequestTask.java b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/RequestTask.java
index b12939e..3849860 100644
--- a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/RequestTask.java
+++ b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/RequestTask.java
@@ -16,6 +16,8 @@
 package com.google.android.sample.testsliceapp;
 
 import android.net.Network;
+import android.os.AsyncTask;
+import android.util.Log;
 
 import java.io.BufferedInputStream;
 import java.io.IOException;
@@ -23,7 +25,11 @@
 import java.net.HttpURLConnection;
 import java.net.URL;
 
-class RequestTask{
+class RequestTask extends AsyncTask<Network, Integer, Integer> {
+    protected Integer doInBackground(Network... network) {
+        ping(network[0]);
+        return 0;
+    }
     String ping(Network network) {
         URL url = null;
         try {
@@ -32,8 +38,12 @@
         }
         if (url != null) {
             try {
-                return httpGet(network, url);
+                Log.d("SliceTest", "ping " + url);
+                String result = httpGet(network, url);
+                Log.d("SliceTest", "result " + result);
+                return result;
             } catch (Exception e) {
+                Log.d("SliceTest", "exception: " + e);
             }
         }
         return "";
@@ -47,6 +57,7 @@
         HttpURLConnection connection = (HttpURLConnection) network.openConnection(httpUrl);
         try {
             InputStream inputStream = connection.getInputStream();
+            Log.d("httpGet", "httpUrl + " + httpUrl);
             return new BufferedInputStream(inputStream).toString();
         } finally {
             connection.disconnect();
diff --git a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/TestCarrierService.java b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/TestCarrierService.java
index b1d019e..daa1d17 100644
--- a/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/TestCarrierService.java
+++ b/testapps/TestSliceApp/app/src/main/java/com/google/android/sample/testsliceapp/TestCarrierService.java
@@ -21,6 +21,7 @@
 import android.service.carrier.CarrierService;
 import android.telephony.CarrierConfigManager;
 import android.telephony.SubscriptionManager;
+import android.util.Log;
 
 /**
  * Carrier Service that sets the carrier config upon being bound by the system. Requires UICC
@@ -32,11 +33,13 @@
         CarrierConfigManager cfgMgr =
                 (CarrierConfigManager) getSystemService(Context.CARRIER_CONFIG_SERVICE);
         cfgMgr.notifyConfigChangedForSubId(SubscriptionManager.getDefaultSubscriptionId());
+        Log.d("TestCarrierService", "onCreate + ");
     }
 
     @Override
     public PersistableBundle onLoadConfig(CarrierIdentifier carrierIdentifier) {
         PersistableBundle config = new PersistableBundle();
+        Log.d("TestCarrierService", "onLoadConfig + ");
         return config;
     }
 }
diff --git a/testapps/TestSliceApp/app/src/main/res/layout/fragment_c_b_s.xml b/testapps/TestSliceApp/app/src/main/res/layout/fragment_c_b_s.xml
index ac2ef9d..5305b53 100644
--- a/testapps/TestSliceApp/app/src/main/res/layout/fragment_c_b_s.xml
+++ b/testapps/TestSliceApp/app/src/main/res/layout/fragment_c_b_s.xml
@@ -8,9 +8,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:id="@+id/frameLayoutCBS">
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
+<androidx.constraintlayout.widget.ConstraintLayout
     android:id="@+id/frameLayout3"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ -26,23 +24,26 @@
       android:id="@+id/requestcbs"
       android:layout_width="186dp"
       android:layout_height="57dp"
+      android:layout_marginTop="164dp"
       android:text="Request Network"
-      tools:layout_editor_absoluteX="120dp"
-      tools:layout_editor_absoluteY="154dp" />
+      app:layout_constraintTop_toTopOf="parent"
+      tools:layout_editor_absoluteX="112dp" />
   <Button
       android:id="@+id/releasecbs"
       android:layout_width="187dp"
       android:layout_height="61dp"
+      android:layout_marginTop="124dp"
       android:text="Release Network"
-      tools:layout_editor_absoluteX="119dp"
-      tools:layout_editor_absoluteY="273dp" />
+      app:layout_constraintTop_toBottomOf="@+id/requestcbs"
+      tools:layout_editor_absoluteX="119dp" />
   <Button
       android:id="@+id/pingcbs"
       android:layout_width="186dp"
       android:layout_height="55dp"
       android:text="Ping"
-      tools:layout_editor_absoluteX="120dp"
-      tools:layout_editor_absoluteY="379dp" />
+      app:layout_constraintBottom_toBottomOf="parent"
+      app:layout_constraintTop_toBottomOf="@+id/releasecbs"
+      tools:layout_editor_absoluteX="120dp" />
 </androidx.constraintlayout.widget.ConstraintLayout>
 </FrameLayout>
 </RelativeLayout>
\ No newline at end of file
diff --git a/testapps/TestSliceApp/app/src/main/res/layout/fragment_prioritize_latency.xml b/testapps/TestSliceApp/app/src/main/res/layout/fragment_prioritize_latency.xml
index 9527d69..b040995 100644
--- a/testapps/TestSliceApp/app/src/main/res/layout/fragment_prioritize_latency.xml
+++ b/testapps/TestSliceApp/app/src/main/res/layout/fragment_prioritize_latency.xml
@@ -8,51 +8,52 @@
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:id="@+id/frameLayoutLatency">
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/frameLayout"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    tools:context=".PrioritizeLatency" >
-  <Button
-      android:id="@+id/requestlatency"
-      android:layout_width="wrap_content"
-      android:layout_height="wrap_content"
-      android:text="RequestNetwork"
-      app:layout_constraintBottom_toTopOf="@+id/button6"
-      app:layout_constraintEnd_toEndOf="parent"
-      app:layout_constraintHorizontal_bias="0.461"
-      app:layout_constraintStart_toStartOf="parent"
-      app:layout_constraintTop_toTopOf="parent"
-      app:layout_constraintVertical_bias="0.717" />
-  <Button
-      android:id="@+id/releaselatency"
-      android:layout_width="wrap_content"
-      android:layout_height="wrap_content"
-      android:layout_marginBottom="76dp"
-      android:text="Release Network"
-      app:layout_constraintBottom_toTopOf="@+id/button7"
-      app:layout_constraintEnd_toEndOf="parent"
-      app:layout_constraintHorizontal_bias="0.478"
-      app:layout_constraintStart_toStartOf="parent" />
-  <Button
-      android:id="@+id/pinglatency"
-      android:layout_width="182dp"
-      android:layout_height="42dp"
-      android:layout_marginBottom="308dp"
-      android:text="Ping"
-      app:layout_constraintBottom_toBottomOf="parent"
-      app:layout_constraintEnd_toEndOf="parent"
-      app:layout_constraintHorizontal_bias="0.471"
-      app:layout_constraintStart_toStartOf="parent" />
-  <TextView
-      android:id="@+id/textView"
-      android:layout_width="371dp"
-      android:layout_height="52dp"
-      android:text="Prioritize Latency"
-      tools:layout_editor_absoluteX="21dp"
-      tools:layout_editor_absoluteY="1dp" />
-</androidx.constraintlayout.widget.ConstraintLayout>
-    </FrameLayout>
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/frameLayout"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        tools:context=".PrioritizeLatency">
+      <Button
+          android:id="@+id/requestlatency"
+          android:layout_width="183dp"
+          android:layout_height="50dp"
+          android:layout_marginTop="176dp"
+          android:text="RequestNetwork"
+          app:layout_constraintBottom_toTopOf="@+id/button6"
+          app:layout_constraintEnd_toEndOf="parent"
+          app:layout_constraintHorizontal_bias="0.495"
+          app:layout_constraintStart_toStartOf="parent"
+          app:layout_constraintTop_toTopOf="parent"
+          app:layout_constraintVertical_bias="0.717" />
+      <Button
+          android:id="@+id/releaselatency"
+          android:layout_width="183dp"
+          android:layout_height="50dp"
+          android:layout_marginTop="84dp"
+          android:text="ReleaseNetwork"
+          app:layout_constraintBottom_toTopOf="@+id/button6"
+          app:layout_constraintEnd_toEndOf="parent"
+          app:layout_constraintStart_toStartOf="parent"
+          app:layout_constraintTop_toBottomOf="@+id/requestlatency"
+          app:layout_constraintVertical_bias="0.717" />
+      <Button
+          android:id="@+id/pinglatency"
+          android:layout_width="182dp"
+          android:layout_height="42dp"
+          android:layout_marginBottom="92dp"
+          android:text="Ping"
+          app:layout_constraintBottom_toBottomOf="parent"
+          app:layout_constraintEnd_toEndOf="parent"
+          app:layout_constraintHorizontal_bias="0.493"
+          app:layout_constraintStart_toStartOf="parent"
+          app:layout_constraintTop_toBottomOf="@+id/releaselatency" />
+      <TextView
+          android:id="@+id/textView"
+          android:layout_width="371dp"
+          android:layout_height="52dp"
+          android:text="Prioritize Latency"
+          tools:layout_editor_absoluteX="16dp"
+          tools:layout_editor_absoluteY="16dp" />
+    </androidx.constraintlayout.widget.ConstraintLayout>
+  </FrameLayout>
     </RelativeLayout>
\ No newline at end of file
diff --git a/tests/src/com/android/services/telephony/TelephonyConnectionTest.java b/tests/src/com/android/services/telephony/TelephonyConnectionTest.java
index 388fd29..c996e5f 100644
--- a/tests/src/com/android/services/telephony/TelephonyConnectionTest.java
+++ b/tests/src/com/android/services/telephony/TelephonyConnectionTest.java
@@ -14,6 +14,7 @@
 import static org.mockito.Mockito.when;
 
 import android.os.Bundle;
+import android.os.PersistableBundle;
 import android.telecom.Connection;
 import android.telephony.CarrierConfigManager;
 import android.telephony.DisconnectCause;
@@ -25,6 +26,7 @@
 import com.android.internal.telephony.d2d.DtmfTransport;
 import com.android.internal.telephony.d2d.RtpTransport;
 import com.android.internal.telephony.imsphone.ImsPhoneConnection;
+import com.android.phone.PhoneGlobals;
 import com.android.phone.R;
 
 import org.junit.Before;
@@ -212,4 +214,47 @@
             fail("refreshConferenceSupported threw ClassCastException");
         }
     }
+
+    /**
+     * Tests TelephonyConnection#getCarrierConfig never returns a null given all cases that can
+     * cause a potential null.
+     */
+    @Test
+    public void testGetCarrierConfigBehaviorWithNull() throws Exception {
+        TestTelephonyConnectionSimple c = new TestTelephonyConnectionSimple();
+
+        // case: return a valid carrier config (good case)
+        when(c.mPhoneGlobals.getCarrierConfigForSubId(c.getPhone().getSubId())).
+                thenReturn(CarrierConfigManager.getDefaultConfig());
+        assertNotNull(c.getCarrierConfig());
+
+        // case: PhoneGlobals.getInstance().getCarrierConfigForSubId(int) returns null
+        when(c.mPhoneGlobals.getCarrierConfigForSubId(c.getPhone().getSubId()))
+                .thenReturn(null);
+        assertNotNull(c.getCarrierConfig());
+
+        // case: phone is null
+        c.setMockPhone(null);
+        assertNull(c.getPhone());
+        assertNotNull(c.getCarrierConfig());
+    }
+
+    /**
+     * Tests the behavior of TelephonyConnection#isRttMergeSupported(@NonNull PersistableBundle).
+     * Note, the function should be able to handle an empty PersistableBundle and should NEVER
+     * receive a null object as denoted in by @NonNull annotation.
+     */
+    @Test
+    public void testIsRttMergeSupportedBehavior() {
+        TestTelephonyConnection c = new TestTelephonyConnection();
+        //  ensure isRttMergeSupported(PersistableBundle) does not throw NPE when given an Empty PB
+        assertFalse(c.isRttMergeSupported(new PersistableBundle()));
+
+        // simulate the passing situation
+        c.getCarrierConfigBundle().putBoolean(
+                CarrierConfigManager.KEY_ALLOW_MERGING_RTT_CALLS_BOOL,
+                true);
+        assertTrue(c.isRttMergeSupported(c.getCarrierConfig()));
+    }
+
 }
diff --git a/tests/src/com/android/services/telephony/TestTelephonyConnectionSimple.java b/tests/src/com/android/services/telephony/TestTelephonyConnectionSimple.java
new file mode 100644
index 0000000..9dc2551
--- /dev/null
+++ b/tests/src/com/android/services/telephony/TestTelephonyConnectionSimple.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.services.telephony;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import android.content.AttributionSource;
+import android.content.Context;
+import android.os.Process;
+import android.telephony.TelephonyManager;
+
+import com.android.internal.telephony.Phone;
+import com.android.internal.telephony.PhoneConstants;
+import com.android.phone.PhoneGlobals;
+
+import org.mockito.ArgumentMatchers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class TestTelephonyConnectionSimple extends TelephonyConnection{
+
+    @Mock
+    Context mMockContext;
+
+    @Mock
+    PhoneGlobals mPhoneGlobals;
+
+    private Phone mMockPhone;
+
+    public TelephonyConnection cloneConnection() {
+        return this;
+    }
+
+    public TestTelephonyConnectionSimple(){
+        super(null, null, android.telecom.Call.Details.DIRECTION_INCOMING);
+        MockitoAnnotations.initMocks(this);
+
+        AttributionSource attributionSource = new AttributionSource.Builder(
+                Process.myUid()).build();
+
+        mMockPhone    = mock(Phone.class);
+        mMockContext  = mock(Context.class);
+        mPhoneGlobals = mock(PhoneGlobals.class);
+
+        when(mMockPhone.getSubId()).thenReturn(1);
+    }
+
+    public void setMockPhone(Phone newPhone) {
+        mMockPhone = newPhone;
+    }
+
+    @Override
+    public Phone getPhone() {
+        return mMockPhone;
+    }
+
+}