AudioService: focus hardening is SDK-gated

Audio focus restrictions are SDK-gated: check target SDK in
  HardeningEnforcer.
Pass attribution tag and target SDK in HardeningEnforcer.
Use noteOpNoThrow and note focus op just once (no second check
  in MediaFocusControl).

Bug: 341815817
Test: atest AudioFocusTest
Change-Id: I100887fbf9a7d3ff15d87e4915135116f0e2b41a