Update response to Task Manager stops.

1. Don't inform the job it's about to be stopped.
2. Don't reschedule user-visible jobs if they were stopped by the user
   via Task Manager.
3. Kill the app process immediately instead of waiting for the onStopJob
   flow/timeout.

Bug: 261999509
Test: atest FrameworksMockingServicesTests:JobSchedulerServiceTest
Test: atest FrameworksMockingServicesTests:JobStatusTest
Test: atest SystemUITests:FgsManagerControllerTest
Test: Manually stop test app in Task Manager and check JobScheduler logs
Change-Id: I29cecfc4b0988685e78387943154837cd4b72cea