Audio: Flag volume adjustments from hardware keys.

Bug: 19793279
Change-Id: If20d70c13c9e7d1f8a6b31e0069564073d30e2bc
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index cdd6c7f..b789d41 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -4905,7 +4905,8 @@
             return;
         }
         int keyCode = event.getKeyCode();
-        int flags = AudioManager.FLAG_SHOW_UI | AudioManager.FLAG_PLAY_SOUND;
+        int flags = AudioManager.FLAG_SHOW_UI | AudioManager.FLAG_PLAY_SOUND
+                | AudioManager.FLAG_FROM_KEY;
         String pkgName = mContext.getOpPackageName();
         switch (keyCode) {
             case KeyEvent.KEYCODE_VOLUME_UP: