Add swap ratio to compaction dumpsys diagnostics

Add swap ratio to local device diagnostics to more easily debug
compaction system efficiency.

Flag: EXEMPT bugfix
Bug: 391953996
Test: am compact full <process>
Test: dumpsys activity
Unresolved-Comment-Reason: Unresolved comments will be handled in future CL
Change-Id: I913555378794f0450948dbeb2d23840d91d09fef