Only send meeting emails after upsync is confirmed finished

* We were queueing up emails during our upsync, but before the upsync
  was complete.  If there were connection issues, we could pile up
  multiple copies of the same message, each of which would eventually
  get sent out
* Fix is to simply queue up the outgoing mail and send it all after
  the sync operation is complete.

Bug: 2515975
Change-Id: Ide3eb2deb6e959d0637d28efabd613efb3c6e209
1 file changed