In the case that a user has been removed but their jobs still exist on disk, the JobSchedulerService will remove all jobs not associated with current users on boot. Exposed UserManagerService#getUserIds() via UserManagerInternal for quick user id retrieval. Fixes: 38261977 Test: manual Change-Id: Id4b3c0a4142b4818fcd875eef18ea03f3c45ca40 Signed-off-by: Michael Wachenschwanz <mwachens@google.com>