title: Drawable setAlpha not working on android 4.4.2
body: <p>I'm using following function to enable and disable drawables...</p>
  
  <pre><code>public static void setDrawableState(Drawable d, boolean enabled)
  {
      if (d == null)
          return;
      d.mutate(); // so drawables don't share state anymore
      if (enabled)
          d.setAlpha(255);
      else
          d.setAlpha(100);
  }
  </code></pre>
  
  <p>This worked on all phones I've tried yet, now I see it does not seem to work on android 4.4.2 (maybe it's not even version specific).</p>
  
  <p>Is there another (better) way to set the alpha of a drawable? Or am I'm missing something?</p>