Emergency redial implementation

Define connection event to notify
Telecom/InCallUi about change in
account handle after redial and extra
for emergency phone handle.

Test: Unit Tests
Bug: 27059146
Change-Id: Ie72ab2901ec05d972204ed11f115a05b79173c1d

telecomm/java/android/telecom/Connection.java

@@ -826,6 +826,8 @@ public abstract class Connection extends Conferenceable {
         public void onRttInitiationFailure(Connection c, int reason) {}
         public void onRttSessionRemotelyTerminated(Connection c) {}
         public void onRemoteRttRequest(Connection c) {}
+        /** @hide */
+        public void onPhoneAccountChanged(Connection c, PhoneAccountHandle pHandle) {}
     }
 
     /**
@@ -3032,6 +3034,18 @@ public abstract class Connection extends Conferenceable {
         }
     }
 
+    /**
+     * Notifies listeners when phone account is changed. For example, when the PhoneAccount is
+     * changed due to an emergency call being redialed.
+     * @param pHandle The new PhoneAccountHandle for this connection.
+     * @hide
+     */
+    public void notifyPhoneAccountChanged(PhoneAccountHandle pHandle) {
+        for (Listener l : mListeners) {
+            l.onPhoneAccountChanged(this, pHandle);
+        }
+    }
+
     /**
      * Sends an event associated with this {@code Connection} with associated event extras to the
      * {@link InCallService}.