Revert^2 "Add exemptions to flex policy."

57ed8cfb

Exempt DEFAULT+ priority jobs for BFGS+ and exempted apps from flex
policy. LOW and MIN priority jobs will continue to have the flex policy
applied.

Bug: 236261941
Bug: 299329948
Bug: 299346198
Test: atest CtsJobSchedulerTestCases:FlexibilityConstraintTest
Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/job
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/job
Change-Id: Ia4d19e9726db748a63eb422858c208d393a9f3b2