Add master audio balance

Test: Change Balance through Settings, play audio
Bug: 28390736
Change-Id: I6cebd3fa448239999c5d624f10902152d0db679b
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 7a261a9..32f1207 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -274,6 +274,7 @@
     <protected-broadcast android:name="android.media.MASTER_VOLUME_CHANGED_ACTION" />
     <protected-broadcast android:name="android.media.MASTER_MUTE_CHANGED_ACTION" />
     <protected-broadcast android:name="android.media.MASTER_MONO_CHANGED_ACTION" />
+    <protected-broadcast android:name="android.media.MASTER_BALANCE_CHANGED_ACTION" />
     <protected-broadcast android:name="android.media.SCO_AUDIO_STATE_CHANGED" />
     <protected-broadcast android:name="android.media.ACTION_SCO_AUDIO_STATE_UPDATED" />