Prevent other organizer lifecycle events if taskAppeared fails

- In the unlikely scenario that onTaskAppeared() fails, we should not
  send any other organizer events otherwise it violates the expected
  lifecycle of tasks in ShellTaskOrganizer

Bug: 404475663
Flag: EXEMPT bugfix
Test: atest WindowOrganizerTests

Change-Id: I8495d0c296a141b1866c021b6501fbd1242dd33d