Add Toggle Controllers to XML

Autobrightness preference controller was accidentally removed from
display_settings.xml. Given that no tests were broken and this would
be a disaster for phone buddy & inline actions, I have added another
test which keeps a list of valid controllers that should exist in xml.

When more inline controllers types are added, they will be included
in this test.

Fixes: 72564979
Test: robotests
Change-Id: I40fe18f9118af9cec1c201632742d2949ff64be5

tests/robotests/src/com/android/settings/testutils/FakeToggleController.java

@@ -0,0 +1,52 @@
+/*
+ * 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.testutils;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import com.android.settings.core.TogglePreferenceController;
+
+public class FakeToggleController extends TogglePreferenceController {
+
+    private String settingKey = "toggle_key";
+
+    private final int ON = 1;
+    private final int OFF = 0;
+
+    public FakeToggleController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+    }
+
+    @Override
+    public boolean isChecked() {
+        return Settings.System.getInt(mContext.getContentResolver(),
+                settingKey, OFF) == ON;
+    }
+
+    @Override
+    public boolean setChecked(boolean isChecked) {
+        return Settings.System.putInt(mContext.getContentResolver(), settingKey,
+                isChecked ? ON : OFF);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+}