AudioParameter: Document usage of exiting and closing.

Ensure only privileged access.
Log warning message on setParameters failure
to prevent entering standby silently.

Test: adb shell dumpsys media.audio_flinger
Bug: 73175392
Bug: 270480994
Bug: 279106598
Merged-In: Ie38ee93e98ff2164f9076b8b6b7831cc6b7a8896
Change-Id: Ie38ee93e98ff2164f9076b8b6b7831cc6b7a8896
7 files changed