Transferring to a cast device should not close the output switcher

-Close panel only when on pause and stop
-Transfer device would set the play state to "STATE_NONE"
-Add test case

Bug: 152632226
Test: make -j42 RunSettingsRoboTests
Change-Id: Ibf6ce1454b1d5bf3facc07abec15b8735029f2cf

tests/robotests/src/com/android/settings/panel/MediaOutputPanelTest.java

@@ -295,4 +295,19 @@ public class MediaOutputPanelTest {
 
         verify(mCallback).forceClose();
     }
+
+    @Test
+    public void onPlaybackStateChanged_stateFromPlayingToPaused_verifyCallForceClose() {
+        mPanel.onStart();
+        verify(mMediaController).registerCallback(mControllerCbs.capture());
+        final MediaController.Callback controllerCallbacks = mControllerCbs.getValue();
+        when(mPlaybackState.getState()).thenReturn(PlaybackState.STATE_PLAYING);
+        controllerCallbacks.onPlaybackStateChanged(mPlaybackState);
+        verify(mCallback, never()).forceClose();
+
+        when(mPlaybackState.getState()).thenReturn(PlaybackState.STATE_PAUSED);
+        controllerCallbacks.onPlaybackStateChanged(mPlaybackState);
+
+        verify(mCallback).forceClose();
+    }
 }