Don't delete attendees until Event is finally deleted

* Exchange (and potentially other sync adapters) needs to send cancellation
  notices when Events are deleted; this requires that Attendee information
  remain intact until the Event is actually deleted (rather than being marked
  deleted)
* The change is to move the deletion of Attendee rows until the Event is
  actually deleted
* There are also some IDE-compatible formatting changes and a little cleanup

Bug: 2474733
Change-Id: I1fcdfc58bb3341f77b1f1087029db39749851f5e
1 file changed