am: Make setAttachingProcessStatesLSP use internal class

This change migrates the `OomAdjuster.setAttachingProcessStatesLSP()` to
operate directly on `ProcessRecordInternal`. To achieve that, it adds
`getPid`, `useFifoUiScheduling`, and `NotifyTopProcChanged` to abstract
methods in `ProcessRecordInternal`.

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

Change-Id: I6835aaaa4a10d40e1dd134aac5bdca9ee3f04d3a