Add the new settings page for lock screen notifs

Add a new empty settings page, which is flag-guarded. When the flag
is disabled, show the original Notifications on lock screen
tri-state switch, otherwise show the new page.

Bug: 367455695
Flag: com.android.server.notification.notification_lock_screen_settings
Test: atest LockScreenNotificationsPreferenceControllerTest

Change-Id: I8a81ad651626f39380767b2c9cfa2f1c19d0e7c5

src/com/android/settings/notification/LockScreenNotificationsPreferencePageFragment.java

@@ -0,0 +1,56 @@
+/*
+ * 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.settings.notification;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+
+import com.android.server.notification.Flags;
+import com.android.settings.R;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.search.SearchIndexable;
+
+/**
+ * Fragment for notifications on lock screen preference page.
+ */
+@SearchIndexable
+public class LockScreenNotificationsPreferencePageFragment extends DashboardFragment {
+
+    @Override
+    public int getMetricsCategory() {
+        //TODO(b/367455695): create a new metrics category
+        return SettingsEnums.SETTINGS_LOCK_SCREEN_PREFERENCES;
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.lock_screen_notifications_settings;
+    }
+    @Override
+    protected String getLogTag() {
+        return "LockScreenNotificationsPreferenceFragment";
+    }
+
+    public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
+            new BaseSearchIndexProvider(R.xml.lock_screen_notifications_settings) {
+                @Override
+                protected boolean isPageSearchEnabled(Context context) {
+                    return Flags.notificationLockScreenSettings();
+                }
+            };
+}