Add global HTTP proxy to Privacy Settings page

This CL allows the user to see on the Enterprise Privacy Settings
page whether the admin set a global HTTP proxy.

Test: make RunSettingsRoboTests
Bug: 32692748

Change-Id: I3c7c46f806f39c90425fd8e098a749f3cc1e9278

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

@@ -17,6 +17,7 @@
 package com.android.settings.vpn2;
 
 import android.net.ConnectivityManager;
+import android.net.ProxyInfo;
 
 public class ConnectivityManagerWrapperImpl implements ConnectivityManagerWrapper {
 
@@ -30,4 +31,9 @@ public class ConnectivityManagerWrapperImpl implements ConnectivityManagerWrappe
     public String getAlwaysOnVpnPackageForUser(int userId) {
         return mCm.getAlwaysOnVpnPackageForUser(userId);
     }
+
+    @Override
+    public ProxyInfo getGlobalProxy() {
+        return mCm.getGlobalProxy();
+    }
 }