title: background drawable for using layer-list not wrapping the parent screen
body: <p>I am trying to re-create a splash screen to conform to Google standard. I tried creating a background drawable for my splash screen which I'll be setting in theme itself. But I am looking for a way to make the bitmap match the parent. </p>
  
  <p>Below is my drawable code: splash_screen_bg.xml</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt; 
   &lt;layer-list xmlns:android="http://schemas.android.com/apk/res/android"&gt; 
   &lt;item android:gravity="center"&gt;
   &lt;bitmap android:src="@drawable/logo_show" android:gravity="center" /&gt;
   &lt;/item&gt;
   &lt;/layer-list&gt;
  </code></pre>
  
  <p>Here is code where I am setting this drawable as background of an activity:</p>
  
  <pre><code> &lt;style name="SpTheme" parent="SearchActivityTheme.NoActionBar"&gt; 
   &lt;item name="colorPrimaryDark"&gt;@color/colorAccentXDark&lt;/item&gt;
   &lt;item name="android:alertDialogTheme"&gt;@style/AlertDialogTheme&lt;/item&gt; 
   &lt;item name="android:windowBackground"&gt;@drawable/splash_screen_bg&lt;/item&gt;
   &lt;/style&gt;
  </code></pre>