title: Elevation not working for ImageView
body: <p>Elevation for ImageView is not working. I declared ImageView in XML like this:</p>
  
  <pre><code>&lt;ImageView
          android:id="@+id/image"
          android:layout_width="100dp"
          android:layout_height="50dp"
          android:elevation="10dp"
          android:src="@drawable/youtube" /&gt;
  </code></pre>
  
  <p>What else should I do for elevation to work properly for ImageView?</p>