Enforce minimum job time windows.

Set a minimum difference between a job's latency and deadline to give
the system time to optimize execution decisions.

Bug: 311402873
Bug: 297106511
Bug: 299329948
Bug: 236261941
Test: atest CtsJobSchedulerSharedUidTestCases
Test: atest CtsJobSchedulerTestCases
Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/job
Test: atset frameworks/base/services/tests/servicestests/src/com/android/server/job
Change-Id: Ia6a7f1ddfdcef3fb7298543170b03ba679e0779c