psc: Move isolated and isSdkSandbox to ProcessRecordInternal

This CL refactors the `isolated` and `isSdkSandbox` fields from
`ProcessRecord` to `ProcessRecordInternal`. It's the preparation to
decouple OomAdjuster with ProcessRecord.

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

Change-Id: I75b4b8f3023f0371399cdcc81e70c435b4262aa3