Use SystemUpdateManager to provide system update info.

Change-Id: I38b631cda8aa63e478c74625eba3d18f9a5723bd
Fixes: 36874007
Test: robotests

src/com/android/settings/system/AdditionalSystemUpdatePreferenceController.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2016 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.system;
+
+import android.content.Context;
+
+import com.android.settings.core.BasePreferenceController;
+
+public class AdditionalSystemUpdatePreferenceController extends BasePreferenceController {
+
+    private static final String KEY_UPDATE_SETTING = "additional_system_update_settings";
+
+    public AdditionalSystemUpdatePreferenceController(Context context) {
+        super(context, KEY_UPDATE_SETTING);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return mContext.getResources().getBoolean(
+                com.android.settings.R.bool.config_additional_system_update_setting_enable)
+                ? AVAILABLE
+                : DISABLED_UNSUPPORTED;
+    }
+}