Use searchable="false" to suppress nonIndexables.

When possible, remove or simplify getNonIndexable() logic in fragments,
and use searchable="false" in xml to suppress index.

Change-Id: I5bdf5bc7d5494a64cdd9e230a51321a4b210af69
Fixes: 112608186
Test: robotest and manual search

src/com/android/settings/dream/DreamEntryPreferenceController.java

@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2018 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.dream;
-
-import android.content.Context;
-
-import com.android.settings.core.BasePreferenceController;
-
-public class DreamEntryPreferenceController extends BasePreferenceController {
-
-    public DreamEntryPreferenceController(Context context, String preferenceKey) {
-        super(context, preferenceKey);
-    }
-
-    @Override
-    public int getAvailabilityStatus() {
-        return AVAILABLE_UNSEARCHABLE;
-    }
-}