title: List<SkuDetails> to json gives incomplete json list
body: <p>I receive a <code>List&lt;SkuDetails&gt;</code> as following:</p>
  <pre><code>public void onSkuDetailsResponse(BillingResult billingResult,
                                  List&lt;SkuDetails&gt; skuDetailsList) {
      Gson gson = new Gson();
      String json = gson.toJson(skuDetailsList);
      Log.d(TAG, json);
  </code></pre>
  <p><a href="https://developer.android.com/reference/com/android/billingclient/api/SkuDetails" rel="nofollow noreferrer">SkuDetails doc</a></p>
  <p>Then I get this unfinished json:</p>
  <pre><code>[{&quot;zza&quot;:&quot;{\&quot;skuDetailsToken\&quot;:\&quot;s-r3R-r\&quot;,\&quot;productId\&quot;:\&quot;chill_lo_fi\&quot;,\&quot;type\&quot;:\&quot;inapp\&quot;,\&quot;price\&quot;:\&quot;R$ 5,49\&quot;,\&quot;price_amount_micros\&quot;:5490000,\&quot;price_currency_code\&quot;:\&quot;BRL\&quot;,\&quot;title\&quot;:\&quot;Chill Lo-Fi (SDoubleKick - Footdrum - SS)\&quot;,\&quot;description\&quot;:\&quot;Chill Lo-Fi sound pack\&quot;}&quot;,&quot;zzb&quot;:{&quot;nameValuePairs&quot;:{&quot;skuDetailsToken&quot;:&quot;s-r3R-r&quot;,&quot;productId&quot;:&quot;chill_lo_fi&quot;,&quot;type&quot;:&quot;inapp&quot;,&quot;price&quot;:&quot;R$ 5,49&quot;,&quot;price_amount_micros&quot;:5490000,&quot;price_currency_code&quot;:&quot;BRL&quot;,&quot;title&quot;:&quot;Chill Lo-Fi (SDoubleKick - Footdrum - SS)&quot;,&quot;description&quot;:&quot;Chill Lo-Fi sound pack&quot;}}},{&quot;zza&quot;:&quot;{\&quot;skuDetailsToken\&quot;:\&quot;a-r\&quot;,\&quot;productId\&quot;:\&quot;percussion_and_fx\&quot;,\&quot;type\&quot;:\&quot;inapp\&quot;,\&quot;price\&quot;:\&quot;R$ 5,49\&quot;,\&quot;price_amount_micros\&quot;:5490000,\&quot;price_currency_code\&quot;:\&quot;BRL\&quot;,\&quot;title\&quot;:\&quot;Percussion and Fx (SDoubleKick - Footdrum - SS)\&quot;,\&quot;description\&quot;:\&quot;Percussion and Fx sound pack\&quot;}&quot;,&quot;zzb&quot;:{&quot;nameValuePairs&quot;:{&quot;skuDetailsToken&quot;:&quot;s-dsf3
  </code></pre>
  <p>You can see that this is a list, it should have printed correctly, but I get, in the end:</p>
  <pre><code>&quot;zzb&quot;:{&quot;nameValuePairs&quot;:{&quot;skuDetailsToken&quot;:&quot;s-dsf3
  </code></pre>
  <p>Because of that, when I reconstruct this gson into an object, I get an exception</p>