title: getSkuDetails() returns empty result for subscriptions in IAB V3
body: <p>I am using in App Billing Version 3. </p>
  
  <p>when i query for SKU details of Managed Product , I am getting results. </p>
  
  <p>But when i query for SKU details of Subscription , it returns empty list</p>
  
  <pre><code>skuDetails = mService.getSkuDetails(3, 
                          getPackageName(), "inapp", querySkus);
  </code></pre>
  
  <p>can anyone help in this ?</p>