Update SoundSettings to extend DashboardFragment.

- initial round of refactoring SoundSettings to use DashboardFragment.
- add controller for Cast, Do not disturb, Alarm volume, Media volume,
  Ring volume and Notification volume.

Bug: 32276590
Test: make RunSettingsRoboTests
Change-Id: I5c02a344bff5117bfce93d7ccac650fccc82d2b0

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

@@ -0,0 +1,56 @@
+/*
+ * 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.notification;
+
+import android.content.Context;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.support.v7.preference.Preference;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.settings.accounts.AccountRestrictionHelper;
+import com.android.settings.core.PreferenceController;
+import com.android.settingslib.RestrictedPreference;
+
+/**
+ * Base class for preference controller that handles preference that enforce adjust volume
+ * restriction
+ */
+public abstract class AdjustVolumeRestrictedPreferenceController extends PreferenceController {
+
+    private AccountRestrictionHelper mHelper;
+
+    public AdjustVolumeRestrictedPreferenceController(Context context) {
+        this(context, new AccountRestrictionHelper(context));
+    }
+
+    @VisibleForTesting
+    AdjustVolumeRestrictedPreferenceController(Context context, AccountRestrictionHelper helper) {
+        super(context);
+        mHelper = helper;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        if (!(preference instanceof RestrictedPreference)) {
+            return;
+        }
+        mHelper.enforceRestrictionOnPreference((RestrictedPreference) preference,
+                UserManager.DISALLOW_ADJUST_VOLUME, UserHandle.myUserId());
+    }
+
+}