Remove CPU_TIME for core processes.

Core UIDs can be cached and be allowed to be frozen. Instead, rely on
persistent getting all capabilities (including CPU_TIME) to propagate
the capability from "core" processes.

Flag: com.android.server.am.use_cpu_time_capability

Test: atest FrameworksMockingServicesTests:ServiceBindingOomAdjPolicyTest
Test: atest FrameworksMockingServicesTests:MockingOomAdjusterTests

Bug: 370817323
Change-Id: I86cc3a12541d7343062554df4c9c7005580c4991