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
diff --git a/services/mediacodec/android.hardware.media.omx@1.0-service.rc b/services/mediacodec/android.hardware.media.omx@1.0-service.rc
index 845e5cc..b5f9ab0 100644
--- a/services/mediacodec/android.hardware.media.omx@1.0-service.rc
+++ b/services/mediacodec/android.hardware.media.omx@1.0-service.rc
@@ -1,6 +1,6 @@
 service vendor.media.omx /vendor/bin/hw/android.hardware.media.omx@1.0-service
     class main
     user mediacodec
-    group camera drmrpc mediadrm
+    group camera drmrpc mediadrm audio
     ioprio rt 4
     task_profiles ProcessCapacityHigh