title: Prevent white screen flash on TWA, occurring between ending of splash screen and opening of Custom Tabs context
body: <p>I have a TWA that problematically flashes a white screen after the splash screen is displayed and before the custom tab mounts and renders my web content.</p>
  
  <p>My application is using a theme that extends <code>Theme.AppCompat.Light.NoActionBar</code>, which merely configures my splash screen for the app. Configuration is like so:</p>
  
  <pre><code>    &lt;style name="Theme.TwaSplash" parent="Theme.AppCompat.Light.NoActionBar"&gt;
          &lt;item name="android:windowNoTitle"&gt;true&lt;/item&gt;
          &lt;item name="android:backgroundDimEnabled"&gt;false&lt;/item&gt;
          &lt;item name="android:windowBackground"&gt;@drawable/splash&lt;/item&gt;
      &lt;/style&gt;
  </code></pre>
  
  <p>This successfully configures my splash screen to render a black background with an icon. However, immediately after the splash screen is show, there is a flash of white in the app. After the white screen, my web content is rendered as a TWA with Custom Tabs.</p>
  
  <p>None of the configuration options for the theme change this behaviour sadly, including setting background colors. To me, it seems as though the flash of white screen occurs whilst the custom tabs Activity tries to mount itself. Is this the case, and is there a way to remove this flash of white?</p>