Add Always on VPN to Privacy Settings page

This CL adds information about always-on VPNs to the Enterprise
Privacy Settings page.

Test: make RunSettingsRoboTests
Bug: 32692748

Change-Id: I2b59e2ec4c55308b323aaa478cd9c847fe0b4b55

src/com/android/settings/vpn2/ConnectivityManagerWrapper.java

@@ -0,0 +1,33 @@
+/*
+ * 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.vpn2;
+
+/**
+ * This interface replicates a subset of the android.net.ConnectivityManager (CM). The interface
+ * exists so that we can use a thin wrapper around the CM in production code and a mock in tests.
+ * We cannot directly mock or shadow the CM, because some of the methods we rely on are marked as
+ * hidden and are thus invisible to Robolectric.
+ */
+public interface ConnectivityManagerWrapper {
+
+    /**
+     * Calls {@code ConnectivityManager.getAlwaysOnVpnPackageForUser()}.
+     *
+     * @see android.net.ConnectivityManager#getAlwaysOnVpnPackageForUser
+     */
+   String getAlwaysOnVpnPackageForUser(int userId);
+}