Add aconfig flag for fixing the missing HUN removal animation for group

Add aconfig flag for fixing the missing HUN removal animation for HUNs
that are posted as a group, but not showing as a group HUN.

Bug: 343475993
Test: n/a
Flag: com.android.systemui.notification_group_hun_removal_animation_fix
Change-Id: Ic997737c839974a6710739d868910750f4d9ff39
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 0fdcc7a..b27f0cc 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -217,6 +217,17 @@
 }
 
 flag {
+    name: "notification_group_hun_removal_animation_fix"
+    namespace: "systemui"
+    description: "Fix the lack of hun removal animation for group notifications"
+        "(not GROUP_ALERT_SUMMARY)"
+    bug: "343475993"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}
+
+flag {
     name: "scene_container"
     namespace: "systemui"
     description: "Enables the scene container framework go/flexiglass."