title: Fragment Return Shared Element Transition not working. Need additional View to work
body: <p>I made a shared element transition for fragment. My transition code as below</p>
  
  <pre><code>if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.LOLLIPOP) {
      Transition changeTransform = TransitionInflater.from(this).
      inflateTransition(R.transition.change_image_transform);
      mainFragment.setSharedElementReturnTransition(changeTransform);
      secondFragment.setSharedElementEnterTransition(changeTransform);
  
      FragmentTransaction fragmentTransaction =
      getSupportFragmentManager().beginTransaction();
      fragmentTransaction.addSharedElement(findViewById(R.id.button_view), "MyTransition");
      fragmentTransaction
      .replace(R.id.fragment_container, secondFragment, MainFragment.TAG);
      fragmentTransaction.addToBackStack(null);
      fragmentTransaction.commit();
  } 
  </code></pre>
  
  <p>My transition xml as below</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;transitionSet xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;changeBounds /&gt;
      &lt;changeTransform /&gt;
  &lt;/transitionSet&gt;
  </code></pre>
  
  <p>My mainFragment as below</p>
  
  <pre><code>```&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;View
          android:id="@+id/button_view"
          android:layout_width="match_parent"
          android:layout_height="100dp"
          android:background="#00f"
          android:transitionName="MyTransition"
          android:onClick="clickButton"/&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>My secondFragment as below</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;View
          android:id="@+id/base_view"
          android:layout_width="match_parent"
          android:layout_height="1dp"/&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:padding="20dp"
          android:layout_height="100dp"&gt;
          &lt;View
              android:id="@+id/button_view"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="#0f0"
              android:transitionName="MyTransition"/&gt;
      &lt;/LinearLayout&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>The transition happen from mainFragment to secondFragment smoothly. However upon return from secondFragment to mainFragment, the transition would only be okay if I have the <code>base_view</code> in the secondFragment. If I remove the <code>base_view</code> from the secondFragment, then the returnTransition is not working. Why is the 'additional' view needed to make the return transition happen?</p>