am 821ec8ed: am 48f472f7: am 0369cf98: Cherry pick from Honeycomb Change ID I8d57d12828afab700d76f9b19195817a0adfe080 IAB docs: adds best practices for pending transaction UI

* commit '821ec8edeee7d59396cbee3a370e5cf3d6c7b8b6':
  Cherry pick from Honeycomb Change ID I8d57d12828afab700d76f9b19195817a0adfe080 IAB docs: adds best practices for pending transaction UI