Adding reasons for granting CPU_TIME capabilities

Two new bit fields within the ProcessStateRecord object to denote all
the reaons this process state may have either CPU_TIME or
IMPLICIT_CPU_TIME are added for logs.

Currently, we only use a small set of reasons that are immediately
useful for debugging. All other reasons to grant [IMPLICIT_]CPU_TIME
are bucketed into [IMPLICIT_]CPU_TIME_REASON_OTHER. Granular reasons
of interest can be split out of this bucket as needed.

Flag: com.android.server.am.cpu_time_capability_based_freeze_policy
Test: atest ServiceBindingOomAdjPolicyTest
Test: atest MockingOomAdjusterTests

Bug: 429283517
Change-Id: I17f349656c33407535119e89d1234d3564d4968a