title: Android Licensing - Extras for APK Expansion are missing
body: <p>After many hours of reading through Google's docs, it is obvious that implementing APK expansion download with the whole licensing mechanism takes 60% of my app's code. And yes, I really need to have expansion files (over 100MB)</p>
  
  <p>So, what I did was read through all of those docs about APK expansions, implement them one by one, and test. Everything seems to be working now, until I get to fetching URLs for those expansion files.</p>
  
  <p>The problem I am facing (and I've checked key, dev account, UUID and other obvious stuff) - licensing passes as LICENSED, but no extras are received in the licensing policy response. More specifically, method <code>com.google.android.vending.licensing.APKExpansionPolicy#processServerResponse()</code> has a parameter called <code>rawData</code> which has a field <code>extras</code> inside. In my test case, that <code>extras</code> is always empty.</p>
  
  <p>Now, I tried to download the app through the beta channel (no production apk is available on the store), no expansion files were downloaded even then! I am guessing that my setup is somehow wrong on the Google Play store, but I have no clue what exactly am I missing.. This has become a very painful process for a simple app as this one, implementing dozens of methods and learning tons of APIs just to be able to host one zip file somewhere.. I could have hosted that file myself and implemented the download mechanism ages ago..</p>