Fix service behavior w/r/t onStartCommand, onCreate, onDestroy

* Make sure to null out vars in onDestroy
* Use START_STICKY as return value for onStartCommand
* Start SyncManager from EasAuthenticator callback, rather from the
  authenticator itself (otherwise, the Account might not have been
  created when we start SyncManager)

Change-Id: I54ff8d5586e96f016b365587717710dee3202da8
2 files changed