add impl for getRegisteredPhoneAccounts

Bug: 307609763
Test: CTS coverage
Change-Id: I20106896ff1d03160ca1989f7975a1a9a034b2aa
diff --git a/flags/telecom_api_flags.aconfig b/flags/telecom_api_flags.aconfig
index f3a2b8a..c44bea4 100644
--- a/flags/telecom_api_flags.aconfig
+++ b/flags/telecom_api_flags.aconfig
@@ -30,6 +30,13 @@
 }
 
 flag{
+  name: "get_registered_phone_accounts"
+  namespace: "telecom"
+  description: "When set, self-managed clients can get their own phone accounts"
+  bug: "317132586"
+}
+
+flag{
   name: "transactional_video_state"
   namespace: "telecom"
   description: "when set, clients using transactional implementations will be able to set & get the video state"