Minor improvements in the audio HAL

Bug: 157158109
Test: presubmit
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: I2c7c5e545cef6f37a8a1fc4f3407cec7fd9091f3
Merged-In: I2c7c5e545cef6f37a8a1fc4f3407cec7fd9091f3
4 files changed