Fix issue 4335692: HDMI media volume

Forced music stream volume to max when not muted and output device is HDMI.

Change-Id: Ibd287cea8ae1d3f36fea6651a113bd5cf2dbad13

services/audioflinger/AudioPolicyManagerBase.cpp

@@ -1911,6 +1911,13 @@ float AudioPolicyManagerBase::computeVolume(int stream, int index, audio_io_hand
         device = outputDesc->device();
     }
 
+    // if volume is not 0 (not muted), force media volume to max on digital output
+    if (stream == AudioSystem::MUSIC &&
+        index != mStreams[stream].mIndexMin &&
+        device == AudioSystem::DEVICE_OUT_AUX_DIGITAL) {
+        return 1.0;
+    }
+
     volume = volIndexToAmpl(device, streamDesc, index);
 
     // if a headset is connected, apply the following rules to ring tones and notifications