Add missing copyright

Test: make
Fixes: 271854104
Change-Id: I55296481ee00eded9123c458167d14e9272918ee

packages/SystemUI/src/com/android/systemui/statusbar/notification/collection/coordinator/GroupCountCoordinator.kt

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2023 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.collection.coordinator
 
 import android.util.ArrayMap