title: Creating GCM Push Messages with action buttons
body: <p>I have seen a few apps that send push notifications that have custom buttons to take certain actions.</p>
  
  <p>I have gone through the GCM push notification server document here:
  <a href="https://developer.android.com/google/gcm/server-ref.html#table1" rel="noreferrer">https://developer.android.com/google/gcm/server-ref.html#table1</a></p>
  
  <p>but there is no reference on how to do this.</p>