Clear account incomplete flag properly; handle unusual flow

* We waited to clear the incomplete flag until security was agreed
  to, but this can lead to accounts left incomplete; we now clear
  the flag as soon as the AccountManager account is created (by
  convention, this is when the EmailProvider account is complete)
* Also, allow onDone() to be called more than once with a saved
  account, leaving cleanly, rather than throwing a runtime
  exception

Bug: 5016792
Change-Id: Ib5fc44ac045a1dd9bd5d63f922c037ed637d5341
1 file changed