Handle moreAvailable true w/o changes (#2189704) DO NOT MERGE

* 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: Icf45efbc24331c874c820b7b177e39b16df445d8
1 file changed