27/n: Slightly update/fix ClientMonitor.FinishCallback

1) Adds "success" parameter so callers can know if the operation
   succeeded. This can be used for operations like remove, where
   the authenticatorId needs to be updated when all templates are
   remove.
2) Moves ClientMonitor#stopHalOperation to AcquisitionClient, since
   AcquisitionClient (and its subclasses Enroll/Auth) are the only
   cancellable tasks.

Bug: 157790417

Test: Builds
Change-Id: Idaffc65f491dcdff2aacb4934b7d1cfa89807a79