Flag to throttle HUNs during avalanche

Bug: 307288824
Test: atest SystemUITests
Flag: ACONFIG notification_throttle_hun DEVELOPMENT

Change-Id: Ie44455a1afeea5baf842c7e42988f362128fa639
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index c26d5f5..5710f09 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -46,6 +46,13 @@
 }
 
 flag {
+    name: "notification_throttle_hun"
+    namespace: "systemui"
+    description: "During notification avalanche, throttle HUNs showing in fast succession."
+    bug: "307288824"
+}
+
+flag {
     name: "scene_container"
     namespace: "systemui"
     description: "Enables the scene container framework go/flexiglass."