title: Cannot return to portrait mode after pressing fullscreen icon in YoutubePlayerFragment
body: <p>I'm learning to add a youtube video on my fragment, everything is fine until I press fullscreen. After exiting fullscreen, the screen is in landscape mode.</p>
  
  <p>FragmentTwo.java code:</p>
  
  <pre><code>@Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
                           Bundle savedInstanceState) {
  
      // Inflate the layout for this fragment
      View view =  inflater.inflate(R.layout.fragment_fragment_two, container, false);
      textView = view.findViewById(R.id.textView_title);
      YouTubePlayerSupportFragment youTubePlayerFragment = new YouTubePlayerSupportFragment();
      youTubePlayerFragment.initialize(getString(R.string.youtube_api_key), this);
      FragmentManager fragmentManager = getFragmentManager();
      FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
      fragmentTransaction.replace(R.id.frame_video, youTubePlayerFragment);
      fragmentTransaction.commit();
  
      //Get the title of the video 
      textView.setText(getArguments().getString("1"));
      return view;
  }
  
  @Override
  public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer youTubePlayer, boolean b) {
      if(!b) {
          youTubePlayer.cueVideo(getArguments().getString("8"));
      }
  }
  
  @Override
  public void onInitializationFailure(YouTubePlayer.Provider provider, YouTubeInitializationResult youTubeInitializationResult) {
      Toast.makeText(getContext(), "Fail", Toast.LENGTH_SHORT).show();
  }
  </code></pre>
  
  <p>And my .xml file:</p>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/youtube_frame"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  tools:context="com.example.gameapp.FragmentTwo"&gt;
  
  &lt;!-- TODO: Update blank fragment layout --&gt;
  
  
  &lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;FrameLayout
          android:id="@+id/frame_video"
          android:layout_width="match_parent"
          android:layout_height="250sp"
          android:layout_alignParentLeft="true"&gt;&lt;/FrameLayout&gt;
  
      &lt;TextView
          android:id="@+id/textView_title"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentStart="true"
          android:layout_below="@+id/frame_video"
          android:paddingBottom="5dp"
          android:paddingRight="5dp"
          android:textColor="@android:color/black"
          android:textSize="15sp" /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p></p>
  
  <p>I tried setting all the layouts' orientation to "vertical" but nothing happens. I have to press back button to get rid of it, which is too much inconvient. Can someone show me how to solve this? Thanks in advance!</p>