Add action to query <Set Audio Volume Level> support

The action sends <Set Audio Volume Level> with an operand that indicates
no change in volume level. The target device supports the message if it
does not respond with <Feature Abort>.

Bug: 199144863
Test: atest SetAudioVolumeLevelDiscoveryActionTest
Change-Id: I958029a4805d68ef8b18458715408fc72e025e82
6 files changed