Add test cases for highlight Preference click behavior

On large screen Activity embedding devices, Settings homepage
shows a highlighted Preference which is mapped to current
right pane.

For better UX, when users click again on a highlighted Preference,
it should not launch SubSettings.

Fix: 236275503
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.dashboard.DashboardFeatureProviderImplTest
Change-Id: I222c9b015fb090f359c3c9f4187823477920715b

tests/robotests/src/com/android/settings/testutils/shadow/ShadowSplitController.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2022 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.testutils.shadow;
+
+import android.app.Activity;
+
+import androidx.window.embedding.SplitController;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+
+/**
+ * Shadow class for {@link SplitController} to test embedding activity features.
+ */
+@Implements(SplitController.class)
+public class ShadowSplitController {
+    private static boolean sIsActivityEmbedded;
+
+    @Implementation
+    protected static boolean isActivityEmbedded(Activity activity) {
+        return sIsActivityEmbedded;
+    }
+
+    public static void setIsActivityEmbedded(boolean isActivityEmbedded) {
+        sIsActivityEmbedded = isActivityEmbedded;
+    }
+}
+