Move screen off adjustment delay to JobConcurrencyManager.

First step in refactoring the concurrency code. Moving this constant
over to JCM since it's a small unit that won't be changed and it's only
used by JCM.

Bug: 141645789
Bug: 171305774
Bug: 178119369
Test: atest CtsJobSchedulerTestCases
Test: atest FrameworksMockingServicesTests:JobSchedulerServiceTest
Test: atest FrameworksServicesTests:JobCountTrackerTest
Test: atest FrameworksServicesTests:MaxJobCountsTest
Test: atest FrameworksServicesTests:PrioritySchedulingTest
Change-Id: I2bc3646901fb8d11ec5818ab10fa6653cfd2e684