title: Valid value formats for android:padding?
body: <p>When writing xml files, I know following is working:</p>
  
  <pre><code>android:padding="20px"
  </code></pre>
  
  <p>Are there other valid value formats available for <code>padding</code>? e.g.</p>
  
  <pre><code>android:padding="10px 20px 10px 20px"
  </code></pre>