Always-on VPN.

Adds support for always-on VPN profiles. Users pick an always-on VPN
from list of existing VPN profiles, which must use an IP address for
both VPN server and DNS.  Moved "add" operation into action bar.

Bug: 5756357
Change-Id: I4c7ed7f2a3b027be1baf65c08213336a61f3acfe

res/menu/vpn.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2012 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.
+-->
+
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/vpn_create"
+        android:title="@string/vpn_create"
+        android:icon="@drawable/ic_menu_add"
+        android:showAsAction="always" />
+    <item
+        android:id="@+id/vpn_lockdown"
+        android:title="@string/vpn_menu_lockdown"
+        android:showAsAction="never" />
+</menu>