Adds implementation for the new TelephonyCallback

Adds the impl to pass the HAL state of cellular
simultaneous calling to TelephonyRegistry to notify
listeners.

Bug: 319904227
Test: atest FrameworksTelephonyTests
Change-Id: Iade7b8249b8e02ad8cff2ce92263ab3a3b420a66
diff --git a/flags/Android.bp b/flags/Android.bp
index 3c0deee..8f363b6 100644
--- a/flags/Android.bp
+++ b/flags/Android.bp
@@ -22,16 +22,17 @@
     name: "telephony_flags",
     package: "com.android.internal.telephony.flags",
     srcs: [
-      "data.aconfig",
-      "domainselection.aconfig",
-      "ims.aconfig",
-      "messaging.aconfig",
-      "misc.aconfig",
-      "network.aconfig",
-      "subscription.aconfig",
-      "uicc.aconfig",
-      "satellite.aconfig",
-      "iwlan.aconfig",
-      "telephony.aconfig",
+        "calling.aconfig",
+        "data.aconfig",
+        "domainselection.aconfig",
+        "ims.aconfig",
+        "messaging.aconfig",
+        "misc.aconfig",
+        "network.aconfig",
+        "subscription.aconfig",
+        "uicc.aconfig",
+        "satellite.aconfig",
+        "iwlan.aconfig",
+        "telephony.aconfig",
     ],
 }
diff --git a/flags/calling.aconfig b/flags/calling.aconfig
new file mode 100644
index 0000000..82f932b
--- /dev/null
+++ b/flags/calling.aconfig
@@ -0,0 +1,8 @@
+package: "com.android.internal.telephony.flags"
+
+flag {
+  name: "simultaneous_calling_indications"
+  namespace: "telephony"
+  description: "APIs that are used to notify simultaneous calling changes to other applications."
+  bug: "297446980"
+}
\ No newline at end of file