AudioService: more logs and test for master mute

Add logging and tests for master mute functions.
Refactor master mute implementation for centralized access
to AudioSystem APIs and logging and store current state in
AudioService.

Bug: 288050380
Test: atest AudioServiceTest
Change-Id: I6755f0411253d65ed83c298835cb27b440759f4e
Merged-In: I6755f0411253d65ed83c298835cb27b440759f4e