Provide defaults for android.hardware.audio@7.0-impl

see aosp/1366502.

Bug: 196868480
Bug: 161485545
Test: presubmit
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: Ie582038f2212fbf881497ed3db62ef04bac286f3
Merged-In: Ie582038f2212fbf881497ed3db62ef04bac286f3