am: Remove unused fields from ProcessServiceRecord

The `mConnectionService` and `mRepFgServiceTypes` fields in
`ProcessServiceRecord` are no longer in use.
This change removes these unused fields and their associated
accessors and references in `ActiveServices` and `ServiceRecord`.

Bug: 425766486
Test: m services.core
Test: atest MockingOomAdjusterTests OomAdjusterTests
Test: atest FrameworksServicesTestsRavenwood_ProcessStateController
Flag: EXEMPT pure refactor
Change-Id: Iaf78c77573daba0ec26d019575c8bce1f49003bd