Add bg exemption tracks for foreground only permissions

...by monitoring their app ops.

Previously we're exempting the bg battery usage if certain permissions
are granted. Yet for the foreground only permissions, we should also
check if their app ops are allowed or not - this is evaluated by their
proc state.

Bug: 203105544
Test: atest FrameworksMockingServicesTests:BackgroundRestrictionTest
Test: Manual - launch camera/maps & check dumpsys activity -a
Change-Id: I8fb99e6c9ad054096a889bea4e53230c7361434e