title: Floating Action Button gravity not working
body: <p>I have a floating action button which should be in the bottom right corner, but apparently the gravity isn't working. It is shown in the top left corner. Here is my code:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout android:id="@+id/rl"
              xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              android:layout_width="match_parent"
              android:layout_height="match_parent"&gt;
  
  &lt;ImageView
      android:id="@+id/iv"
      android:layout_width="match_parent"
      android:layout_height="match_parent"/&gt;
  
  &lt;android.support.design.widget.FloatingActionButton
      android:id="@+id/fab"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="bottom|end"
      android:layout_margin="16dp"
      android:src="@mipmap/ic_action_send"
      app:backgroundTint="@color/colorPrimaryDark"
      app:layout_anchor="@id/iv"
      app:layout_anchorGravity="bottom|right|end"/&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>