This is partial implementation of the example V7.0 audio HAL
which passes VTS tests. Note that the 'core' part
of the HAL (IDevice/IStream) isn't implemented yet.
It passes VTS because it doesn't provide any devices
(modules) and the audio HAL isn't the 'default' instance.
Bug: 142480271
Test: atest VtsHalAudioV7_0TargetTest
atest VtsHalAudioEffectV7_0TargetTest
Change-Id: Ie3dd62c5db1cdb5534df4dd7f326c4c8776bf3c4
Rename README -> README.md, reformat it as Markdown.
Provide missing descriptions for some directories.
Bug: 142480271
Test: N/A
Change-Id: Ic6f60a21def4bf210a7e1446454d709f68a13422
