Fix the overlapping problem of the burst of slice updates

Implement a throttle in SliceBackgroundWorker to control slice updates.

Test: robotest
Fixes: 152366832
Change-Id: I8b65d1b57973e036b932172627aca506f4fae3a4

tests/robotests/src/com/android/settings/slices/ShadowSliceBackgroundWorker.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2020 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.settings.slices;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.annotation.RealObject;
+
+@Implements(SliceBackgroundWorker.class)
+public class ShadowSliceBackgroundWorker {
+
+    @RealObject
+    private SliceBackgroundWorker mRealWorker;
+
+    @Implementation
+    protected final void notifySliceChange() {
+        mRealWorker.getContext().getContentResolver().notifyChange(mRealWorker.getUri(), null);
+    }
+}