Index Nightdisplay Settings into search

Adds a SearchIndexProvider into NightDisplaySettings
to index night_display_settings.xml. It will show
up in search as long as ColorDisplayController
is available.

Also, supress the search result for Night Display
under Display settings in favor of the actual toggle.

Test: robotests
Fixes: 69852201

Change-Id: Id014a5ab03e7a6b5fc99f79a1cb41a0c06323f9c

tests/robotests/src/com/android/settings/display/NightDisplaySettingsTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2017 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.display;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+import android.provider.SearchIndexableResource;
+
+import com.android.settings.R;
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION_O)
+public class NightDisplaySettingsTest {
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+    }
+
+    @Test
+    public void testNightDisplayIndexing_containsResource() {
+        List<SearchIndexableResource> resources =
+                NightDisplaySettings.SEARCH_INDEX_DATA_PROVIDER.getXmlResourcesToIndex(mContext,
+                        true /* enabled */);
+
+        List<Integer> indexedXml = new ArrayList<>();
+        for (SearchIndexableResource resource : resources) {
+            indexedXml.add(resource.xmlResId);
+        }
+
+        assertThat(indexedXml).contains(R.xml.night_display_settings);
+    }
+}