Add Volume Controller API usage flag: use_volume_controller

This flag enables sharing VolumeController between VolumeDialogImpl and
Volume Panel via AudioRepository

Flag: com.android.systemui.use_volume_controller
Test: N/A
Bug: 349348461
Change-Id: I578889a82bb9388dd7e854fe9b62a1dd24793b9e
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 83b7455..18fbf77 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -534,6 +534,16 @@
 }
 
 flag {
+    name: "use_volume_controller"
+    namespace: "systemui"
+    description: "Adds Volume Controller signals to the AudioRepository to update volume"
+    bug: "349348461"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}
+
+flag {
     name: "screenshot_action_dismiss_system_windows"
     namespace: "systemui"
     description: "Dismiss existing system windows when starting action from screenshot UI"