Remove SERVICE_FOREGROUND_TIMEOUT_MSG when scheduling service restart.

When scheduling service restart, if the service is waiting to become a foreground service, remove the pending
SERVICE_FOREGROUND_TIMEOUT_MSG msg, and set fgWaiting to false, so next time the service
is brought up, scheduleServiceForegroundTransitionTimeoutLocked() can be called again and
a new SERVICE_FOREGROUND_TIMEOUT_MSG is scheduled in SERVICE_START_FOREGROUND_TIMEOUT
again.

Bug: 218909914
Test: Manual test, crash a service as b/218909914, watch the service is
scheudle to restart and a new SERVICE_FOREGROUND_TIMEOUT_MSG is
scheduled in SERVICE_START_FOREGROUND_TIMEOUT.

Change-Id: I6194c0ff09ad14a5d04e42729207fa5780d06742