Fix # 2467153 (Handle change in attendee status from Calendar UI)

* Fill in this missing piece of meeting related functionality.
* We keep track of the last synced attendee status in the newly
  created syncAdapterData event column
* When this changes, we (in addition to syncing up the change)
  send an email to the organizer (unless we're the organizer, of

Bug: 2467153
Change-Id: I6332fb6d0839e33d4c54bd4358ee0f154bff6612
1 file changed