Fix volume controls show media instead of call volume during a call.

- On some apps like Signal, When the app is in the foreground and there
is a active phone call, volume controls show media volume control
instead of call volume control.
- Investigation showed that with apps having the right behaviour
"MediaSession.dispatchVolumeKeyEvent" is called, while with apps having
the wrong behaviour
"MediaSessionService.dispatchVolumeKeyEventToSessionAsSystemService" is
called.
- Following this guided to the cause of the steps to reproduce it in
other apps by calling "Activty.setMediaController".
- Issue was reproducible on the Sample MediaRouter App.
- Fixed it through checking not being in a call before forwarding the
volume event to the session.

Bug: 240705522
Test: Manual using Signal App / Youtube and Sample MediaRouter App.
Change-Id: Iabac3c80631fd429daba23454488fceedbcc584d

core/java/com/android/internal/policy/PhoneWindow.java

@@ -1938,9 +1938,9 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
             case KeyEvent.KEYCODE_VOLUME_UP:
             case KeyEvent.KEYCODE_VOLUME_DOWN:
             case KeyEvent.KEYCODE_VOLUME_MUTE: {
-                // If we have a session send it the volume command, otherwise
-                // use the suggested stream.
-                if (mMediaController != null) {
+                // If we have a session and no active phone call send it the volume command,
+                // otherwise use the suggested stream.
+                if (mMediaController != null && !isActivePhoneCallKnown()) {
                     getMediaSessionManager().dispatchVolumeKeyEventToSessionAsSystemService(event,
                             mMediaController.getSessionToken());
                 } else {
@@ -1991,6 +1991,18 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
         return false;
     }
 
+    private boolean isActivePhoneCallKnown() {
+        boolean isActivePhoneCallKnown = false;
+        AudioManager audioManager =
+                (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
+        int audioManagerMode = audioManager.getMode();
+        if (audioManagerMode == AudioManager.MODE_IN_CALL
+                || audioManagerMode == AudioManager.MODE_IN_COMMUNICATION) {
+            isActivePhoneCallKnown = true;
+        }
+        return isActivePhoneCallKnown;
+    }
+
     private KeyguardManager getKeyguardManager() {
         if (mKeyguardManager == null) {
             mKeyguardManager = (KeyguardManager) getContext().getSystemService(