[audio] Add full hardening metrics

Track ops for OP_CONTROL_AUDIO in addition to OP_CONTROL_PARTIAL to
properly plumb metrics for apps which would be restricted at a higher
enforcement level.

Actual enforcement for full restriction is protected via another
flag or shell command. Split exemption into tri-state which represents
whether full, partial, or no enforcement is enabled.

Bug: 376481063
Test: atest AudioPlaybackForegroundTests at different flag levels
Flag: com.android.media.audio.hardening_strict
Change-Id: I6356e00ea7468f6b1f7ed507a4adcbd4d8a25cca