title: ImageButton elevation issue
body: <p>Good afternoon, I am trying to create en ImageButton with a shadow.</p>
  
  <p>To do that :</p>
  
  <pre><code>&lt;LinearLayout
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_vertical"
      android:padding="5sp"&gt;
  
      &lt;ImageButton
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:background="@drawable/circle_shape_little"
          android:src="@drawable/ic_keyboard_arrow_right_black_24dp"
          android:elevation="3sp"/&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>But here is the result :</p>
  
  <p><a href="https://i.stack.imgur.com/NYy39.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NYy39.png" alt="enter image description here"></a></p>
  
  <p>As you can see, the borders are "cut", and I do not know why.</p>
  
  <p>Does anyone can help me ? Thank you.</p>