Fix ANR in one time initializer and unify BroadccastReceivers.

- Merged all three BroadcastReceivers into one.
  (Changed class name because old ones may have been disabled.)

- Use IntentService to perform the tasks in a worker thread.

Note the new receiver will never be disabled.  We always need to start
exchange.SyncManager.

Bug 2722155
Bug 2416929

Change-Id: I8241880fc1ee38d85dcdca7e1d46fc2f6b2d375b
2 files changed