title: Create lock screen media control buttons
body: <p>I am developing a media player for android. As from API 21 Google has deprecated the use of <code>RemoteControlClient</code> in favor of <code>MediaStyle</code> notifications and <code>MediaController</code>. But the new functionality hasn't been added to the support library. So if I want my app to be compatible with older OS versions, I have to do someting like this:</p>
  
  <pre><code>if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.LOLIPOP) {
    // Use MediaController
  } else {
    // Use `RemoteControlClient`
  }
  </code></pre>
  
  <p>Is there a cleaner way to accomplish this? The idea to support two different controller APIs is not so good (in my opinion).</p>
  
  <p>Thanks in advance for any suggestions!</p>