Avoid unnecessary work.

Only requested-expedited-jobs could have their run-in-bg constraint
change (because of EJ quota) without a corresponding call coming through
the ForceAppStandbyListener. Restrict job evaluation to requested-EJ
jobs to avoid making unnecessary/redundant calls for regular jobs.

Bug: 192105110
Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/job
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/job
Test: atest CtsJobSchedulerTestCases
Change-Id: I9acc45e109c32fb77c79df4fe126a9b1845163ff