Add tests under FrameworksMockingServicesTests to presubmit.

Currently, they are setup to run only when there are changes to
AppCompactor.java but we would like to have those run whenever
there are changes to files under com/android/server/am/ so that
tests like MockingOomAdjusterTests can catch regressions sooner.

Test: cd com/android/server/am && atest --test-mapping
Change-Id: Ifc52a0176faa75426d4b86fa26d88a5b214a00b1