Don't allow certain bucket overrides

Don't allow EXEMPT to be overridden
Differentiate between shell and other callers who set
buckets.
Don't allow forced to be modified by bucketeer.
Don't allow bucketeer to modify NEVER bucket.

Fix a locking issue in listeners list. Don't use
the primary lock when calling out to listeners.

Fixes: 70622791
Fixes: 70622338

Test: atest FrameworksServicesTests:AppIdleHistoryTests
      atest FrameworksServicesTests:AppStandbyControllerTests
      atest CtsAppUsageHostTestCases
Change-Id: I22309478b947d6461235f5a77e08c7be86309e4b