title: Cannot cast to AnimatedVectorDrawableCompat in Nougat
body: <p>This is my build.gradle</p>
  
  <pre><code>    defaultConfig {
      ...
      minSdkVersion 21
      targetSdkVersion 26
      vectorDrawables.useSupportLibrary = true
  }
  </code></pre>
  
  <p>and a part of the layout</p>
  
  <pre><code>&lt;ImageView
      android:id="@+id/recents"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:background="?attr/selectableItemBackground"
      android:clickable="true"
      android:scaleType="fitCenter"
      app:srcCompat="@drawable/anim_test"/&gt;
  </code></pre>
  
  <p>and the class cast:</p>
  
  <pre><code>val np = convertView.findViewById&lt;ImageView&gt;(R.id.recents)
  val anim = np.drawable as AnimatedVectorDrawableCompat
  </code></pre>
  
  <p>This works as expected on Lolipop (sdk 21) but fails on Nougat saying:</p>
  
  <pre><code>android.graphics.drawable.AnimatedVectorDrawable cannot be cast to android.support.graphics.drawable.AnimatedVectorDrawableCompat
  </code></pre>
  
  <p>What I dont get is, why does it return an AnimatedVectorDrawableCompat on sdk level 21 at all when AnimatedVectorDrawable is already supported by the system. And why does it return the AnimatedVectorDrawable in Nougat in spite of specifying <code>vectorDrawables.useSupportLibrary = true</code>.</p>