am: Decouple ProcessRecord from OomAdjuster

This refactoring makes the OomAdjuster's methods
`computeServiceHostOomAdjLSP` and `computeProviderHostOomAdjLSP` using
`ProcessRecordInternal` instead of `ProcessRecord`.

To achieve that, it elevates `setTreatLikeActivity`,
`setPendingUiClean`, and `getApplicationUid` to abstract methods in
`ProcessRecordInternal` class.

Bug: 425766486
Test: m services.core
Test: atest MockingOomAdjusterTests OomAdjusterTests
Test: atest FrameworksServicesTestsRavenwood_ProcessStateController
Flag: EXEMPT pure refactor

Change-Id: I67233e38f97c668de858f6993dd9f8a498bd803f