Android videoview - immersive - overlapping controllers

I have a videoview on my app and Im using gogole as a reference to make the video player full screen:

https://developer.android.com/training/system-ui/immersive#java

I was following the instruccion from the above website and i was able to make the videoplayer full screen but I gt a weird problem with my media controller and the device controller(they overlp) and don't know how to fixed any ideas what is the problem.

public class VideoPlayer extends AppCompatActivity {

    VideoView videoView;
    MediaController mediaController;
    private String TAG = VideoPlayer.class.getSimpleName();
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.video_player_activity);

        videoView = (VideoView) findViewById(R.id.videoView);
        mediaController = new MediaController(this);
        videoView.setVideoPath("android.resource://" + getPackageName() + "/" + R.raw.video1);
        mediaController.setAnchorView(videoView);
        videoView.setMediaController(mediaController);
        videoView.start(); 

    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus) {
            hideSystemUI();
        }
    }

    private void hideSystemUI() { 
        View decorView = getWindow().getDecorView();
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            decorView.setSystemUiVisibility(
                    View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION // hide nav bar
                            | View.SYSTEM_UI_FLAG_FULLSCREEN // hide status bar
                            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        }
    } 
    private void showSystemUI() {
        Log.e(TAG, "111");
        View decorView = getWindow().getDecorView();
        decorView.setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    }
}

from Android videoview - immersive - overlapping controllers