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."
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/GroupHunAnimationFix.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/GroupHunAnimationFix.kt
new file mode 100644
index 0000000..5867612
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/shared/GroupHunAnimationFix.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui.statusbar.notification.shared
+
+import com.android.systemui.Flags
+import com.android.systemui.flags.FlagToken
+import com.android.systemui.flags.RefactorFlagUtils
+
+/** Helper for com.android.systemui.Flags.FLAG_NOTIFICATION_GROUP_HUN_REMOVAL_ANIMATION_FIX */
+@Suppress("NOTHING_TO_INLINE")
+object GroupHunAnimationFix {
+    const val FLAG_NAME = Flags.FLAG_NOTIFICATION_GROUP_HUN_REMOVAL_ANIMATION_FIX
+
+    /** A token used for dependency declaration */
+    val token: FlagToken
+        get() = FlagToken(FLAG_NAME, isEnabled)
+
+    /** Are sections sorted by time? */
+    @JvmStatic
+    inline val isEnabled
+        get() = Flags.notificationGroupHunRemovalAnimationFix()
+
+    /**
+     * Called to ensure code is only run when the flag is enabled. This protects users from the
+     * unintended behaviors caused by accidentally running new logic, while also crashing on an eng
+     * build to ensure that the refactor author catches issues in testing.
+     */
+    @JvmStatic
+    inline fun isUnexpectedlyInLegacyMode() =
+        RefactorFlagUtils.isUnexpectedlyInLegacyMode(isEnabled, FLAG_NAME)
+
+    /**
+     * Called to ensure code is only run when the flag is disabled. This will throw an exception if
+     * the flag is enabled to ensure that the refactor author catches issues in testing.
+     */
+    @JvmStatic
+    inline fun assertInLegacyMode() = RefactorFlagUtils.assertInLegacyMode(isEnabled, FLAG_NAME)
+}