Move the Private DNS dialog back to the top level.

Bug: 64133961
Fixes: 74844869
Test: visual test and interaction
      also updated tests and checked they pass
Change-Id: I7c8d50e5941c2a7dd46014932bdace14dc222c80

src/com/android/settings/network/PrivateDnsPreferenceController.java

@@ -0,0 +1,43 @@
+/*
+ * 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.network;
+
+import android.content.Context;
+
+import com.android.settings.R;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+
+public class PrivateDnsPreferenceController extends BasePreferenceController
+        implements PreferenceControllerMixin, LifecycleObserver {
+    private static final String KEY_PRIVATE_DNS_SETTINGS = "private_dns_settings";
+
+    public PrivateDnsPreferenceController(Context context) {
+        super(context, KEY_PRIVATE_DNS_SETTINGS);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_PRIVATE_DNS_SETTINGS;
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+}