SystemUI: Expose VPN icon to allow toggling

Change-Id: I536e7814d486acf5a5c4f3d56b3e46be4928767c

packages/SystemUI/res/drawable/ic_statusbar_vpn.xml

+<!--
+Copyright (C) 2014 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/colorControlNormal">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M12.09,9C11.11,7.5 9.43,6.5 7.5,6.5C4.46,6.5 2,8.96 2,12c0,3.04 2.46,5.5 5.5,5.5c1.93,0 3.61,-1 4.59,-2.5H14v3h6v-3h2V9H12.09zM20,13h-2v3h-2v-3h-5.16c-0.43,1.44 -1.76,2.5 -3.34,2.5C5.57,15.5 4,13.93 4,12c0,-1.93 1.57,-3.5 3.5,-3.5c1.58,0 2.9,1.06 3.34,2.5H20V13z"/>
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M7.5,12m-1.5,0a1.5,1.5 0,1 1,3 0a1.5,1.5 0,1 1,-3 0"/>
+</vector>

packages/SystemUI/res/xml/status_bar_prefs.xml

@@ -124,6 +124,11 @@
 
     <!-- other weird signal stuff -->
 
+    <com.android.systemui.tuner.StatusBarSwitch
+        android:icon="@drawable/ic_statusbar_vpn"
+        android:key="vpn"
+        android:title="@string/legacy_vpn_name" />
+
     <com.android.systemui.tuner.StatusBarSwitch
         android:icon="@*android:drawable/ic_battery"
         android:key="battery"