Fix a BroadcastReceiver leak.

The AccountTypeManager singleton is registered
in the ContactsApplication's getSystemService()
but the call to get the singleton was using the
given context not its .getApplicationContext().
thereby leaking when it was passed an Activity.

This fix seems cleaner then making sure each
caller passes the proper type of context.

Change-Id: I324a05449770e35bfaffb6773a394d63e9ddfb59