Add group audio to vendor.media.omx service

Resolves Qualcomm libs trying to access e.g. /dev/msm_alac and failing.

Referred from: https://source.codeaurora.org/quic/la/platform/frameworks/av/commit?id=150662d

Test: run vts -m VtsHalMediaOmxV1_0TargetAudioDecTest
Change-Id: I28dcc07c00f41ab542b24725d767227854f1b7c9