sysui: handle single master volume case.

Bug: 29446492
Change-Id: Id7414b0cb28d5586f4162850cc67b07c4bee2f6a
(cherry picked from commit 4715f4bb72ed888e392f501a7c1eb8a533e2b33d)
diff --git a/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java b/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
index af6fec2..168683b 100644
--- a/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
@@ -216,6 +216,9 @@
         mExpanded = false;
         mExpandButton = (ImageButton) mDialogView.findViewById(R.id.volume_expand_button);
         mExpandButton.setOnClickListener(mClickExpand);
+
+        mExpandButton.setVisibility(
+                AudioSystem.isSingleVolume(mContext) ? View.GONE : View.VISIBLE);
         updateWindowWidthH();
         updateExpandButtonH();
 
@@ -237,18 +240,21 @@
                 });
 
         if (mRows.isEmpty()) {
-            addRow(AudioManager.STREAM_RING,
-                    R.drawable.ic_volume_ringer, R.drawable.ic_volume_ringer_mute, true);
             addRow(AudioManager.STREAM_MUSIC,
                     R.drawable.ic_volume_media, R.drawable.ic_volume_media_mute, true);
-            addRow(AudioManager.STREAM_ALARM,
-                    R.drawable.ic_volume_alarm, R.drawable.ic_volume_alarm_mute, false);
-            addRow(AudioManager.STREAM_VOICE_CALL,
-                    R.drawable.ic_volume_voice, R.drawable.ic_volume_voice, false);
-            addRow(AudioManager.STREAM_BLUETOOTH_SCO,
-                    R.drawable.ic_volume_bt_sco, R.drawable.ic_volume_bt_sco, false);
-            addRow(AudioManager.STREAM_SYSTEM,
-                    R.drawable.ic_volume_system, R.drawable.ic_volume_system_mute, false);
+            if (!AudioSystem.isSingleVolume(mContext)) {
+                addRow(AudioManager.STREAM_RING,
+                        R.drawable.ic_volume_ringer, R.drawable.ic_volume_ringer_mute, true);
+
+                addRow(AudioManager.STREAM_ALARM,
+                        R.drawable.ic_volume_alarm, R.drawable.ic_volume_alarm_mute, false);
+                addRow(AudioManager.STREAM_VOICE_CALL,
+                        R.drawable.ic_volume_voice, R.drawable.ic_volume_voice, false);
+                addRow(AudioManager.STREAM_BLUETOOTH_SCO,
+                        R.drawable.ic_volume_bt_sco, R.drawable.ic_volume_bt_sco, false);
+                addRow(AudioManager.STREAM_SYSTEM,
+                        R.drawable.ic_volume_system, R.drawable.ic_volume_system_mute, false);
+            }
         } else {
             addExistingRows();
         }