title: How to set the background of Android PopupMenu to White
body: <p>I'm struggling with setting the background of PopupMenu. After googling it for a while, I found it should goes to the app theme. To be more specific, this should be defined in the style.xml.</p>
  
  <pre><code>&lt;style name="AppTheme" parent="AppBaseTheme"&gt;
      &lt;item name="android:popupMenuStyle"&gt;MY_STYLE&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>However, I didn't really figure out which style exactly I should use, as I assume there's a built-in one. I tried with <code>@android:style/Widget.Holo.PopupMenu</code> and <code>@android:style/Widget.Holo.Light.PopupMenu</code>, but with no luck.</p>