Implement TIP2.

Using a rolling window to track reward limits means having no limit on
the number of events that need to be tracked. Switching to buckets for
reward tracking places a cap on TARE's memory usage per app at the cost
of some fidelity.

Bug: 239951405
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/tare
Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/tare
Change-Id: I71beaaf0e2b3fb809314122dc059d1451f080d01