audio policy: report app ops silencing audio recordings

Move audio recording app op monitoring from audio flinger to audio
policy service.
This groups all recording silencing logic in one place and allows for
proper reporting of the audio record silencing via RecordingActivityMonitor.

Bug: 191040756
Test: run app that records audio, then $adb shell appops set <UID> 27 2
Test: atest GtsSuspendAppsTestCases:SuspendPackagesTest
Change-Id: I12c30b1764b5e3d74612c6727a780026295cd367