title: Android FAB icon always black with MaterialComponents theme
body: <p>I'm creating an Android app and I'm using the AndroidX libraries and Material design theme. My app theme on <code>styles.xml</code> is:</p>
  
  <pre><code>&lt;style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar"&gt;
      &lt;item name="colorPrimary"&gt;@color/colorPrimary&lt;/item&gt;
      &lt;item name="colorPrimaryDark"&gt;@color/colorPrimaryDark&lt;/item&gt;
      &lt;item name="colorAccent"&gt;@color/colorAccent&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>I have the following FAB from a custom library:</p>
  
  <pre><code>&lt;com.leinardi.android.speeddial.SpeedDialView
          android:id="@+id/work_log_fab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="bottom|end"
          app:layout_behavior="@string/speeddial_scrolling_view_snackbar_behavior"
          app:sdMainFabClosedSrc="@drawable/ic_add_white_24dp"
          app:sdOverlayLayout="@id/overlay" /&gt;
  </code></pre>
  
  <p>And also tried the default FAB:</p>
  
  <pre><code>&lt;com.google.android.material.floatingactionbutton.FloatingActionButton
          android:id="@+id/fab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="end|bottom"
          android:src="@drawable/ic_add_white_24dp"
          android:layout_margin="16dp" /&gt;
  </code></pre>
  
  <p>No mater the color of the icon (a vector drawable), the icon inside the FAB (from the library and from the default) is always black. I have narrowed down the problem to the material design theme, since using the old <code>Theme.AppCompat.Light.DarkActionBar</code> instead of the new <code>Theme.MaterialComponents.Light.DarkActionBar</code> the icon inside the FAB gets the color of the original vector drawable.</p>
  
  <p>Does anyone know why this is happening and how to solve it?</p>