Update rule of launching media output dialog

-Do not hide Media Output Dialog in Settings, and let dialog handles
-Hide Media output slice panel when launching dialog

Bug: 155822415
Test: make -j50 RunSettingsRoboTests
Change-Id: I16732f625f100b259d6e53c85db40af0ec1652c5

src/com/android/settings/sound/MediaOutputPreferenceController.java

@@ -33,8 +33,6 @@ import com.android.settings.R;
 import com.android.settingslib.Utils;
 import com.android.settingslib.bluetooth.A2dpProfile;
 import com.android.settingslib.bluetooth.HearingAidProfile;
-import com.android.settingslib.core.lifecycle.LifecycleObserver;
-import com.android.settingslib.core.lifecycle.events.OnStop;
 import com.android.settingslib.media.MediaOutputSliceConstants;
 
 import java.util.List;
@@ -47,8 +45,7 @@ import java.util.List;
  * - Media stream captured by remote device
  * - During a call.
  */
-public class MediaOutputPreferenceController extends AudioSwitchPreferenceController
-        implements LifecycleObserver, OnStop {
+public class MediaOutputPreferenceController extends AudioSwitchPreferenceController {
 
     private MediaController mMediaController;
 
@@ -66,15 +63,6 @@ public class MediaOutputPreferenceController extends AudioSwitchPreferenceContro
         }
     }
 
-    @Override
-    public void onStop() {
-        super.onStop();
-        // Media output dialog should not show when onStop
-        mContext.sendBroadcast(new Intent()
-                .setAction(MediaOutputSliceConstants.ACTION_DISMISS_MEDIA_OUTPUT_DIALOG)
-                .setPackage(MediaOutputSliceConstants.SYSTEMUI_PACKAGE_NAME));
-    }
-
     @Override
     public void updateState(Preference preference) {
         if (preference == null) {