No media status is visible in Output Switcher

-Reflash header when get latest media controller

Bug: 152606491
Test: make -j42 RunSettingsRoboTests
Change-Id: I14542a7f8ba921c9d1dbaacf7e01c3ee673527b2

src/com/android/settings/panel/MediaOutputPanel.java

@@ -220,6 +220,7 @@ public class MediaOutputPanel implements PanelContent, LocalMediaManager.DeviceC
                 if (TextUtils.equals(controller.getPackageName(), mPackageName)) {
                     mMediaController = controller;
                     mMediaController.registerCallback(mCb);
+                    mCallback.onHeaderChanged();
                     break;
                 }
             }