Fix lock ordering in JobScheduler

BUG: 17625667
Two part clean-up.
1) Don't try to lock in onControllerStateChanged. Do it in the handleMessage
instead where the rest of the locking is. This is sufficient to fix this bug.
2) The other side of the deadlock came b/c we lock when cancelling and calling
stopTrackingJob. Controllers handle their own locking so this isn't
necessary. B/c of a potential race from the controller side, added an explicit
check for the JSS to only run an expired job if it still exists.

Change-Id: Iaeebbc19437eb5b73e3ced3168f1fc13e564a4be