Handle case of moreAvailable true with no changes (#2189704)

* An Exchange log from Moto has shown sync behavior in which moreAvailable
  is set to true even though there are no changes in the sync response
  (i.e. the SyncKey is unchanged)
* This leads to long-lived looping which impacts battery life
* The fix is to recognize the behavior and prevent looping by
  setting moreAvailable = false

Change-Id: Idef455f3e1170caf4002542ca432d128b3a19e56
1 file changed