Add app_compat flags for hidden api logging

Remove the global settings hidden_api_access_log_sampling_rate and
hidden_api_access_statslog_sampling_rate and replace them with DeviceConfig
values under the app_compat namespace.

Test: m
Test: cts-tradefed run cts-dev -m CtsStatsdHostTestCases -t \
            android.cts.statsd.atom.UidAtomTests#testHiddenApiUsed
Bug: 119217680
Bug: 115322973
Change-Id: I7d3257f572e57b9471883e90789e0ac97a1de483