Do not hardcode media - a11y stream aliasing

Media and accessibility volume aliasing is now modal, and
  now handled in AudioService.

Test: see bug
Bug: 30448020
Change-Id: Ie4e1775163fb65da2c0ed766b477cd9fc1c919d1
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index 5ef0216..a714041 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -4477,9 +4477,7 @@
 
 bool AudioPolicyManager::streamsMatchForvolume(audio_stream_type_t stream1,
                                                audio_stream_type_t stream2) {
-    return ((stream1 == stream2) ||
-            ((stream1 == AUDIO_STREAM_ACCESSIBILITY) && (stream2 == AUDIO_STREAM_MUSIC)) ||
-            ((stream1 == AUDIO_STREAM_MUSIC) && (stream2 == AUDIO_STREAM_ACCESSIBILITY)));
+    return (stream1 == stream2);
 }
 
 uint32_t AudioPolicyManager::getStrategyForStream(audio_stream_type_t stream) {