Fix supplimentary network connections with VPNs

Enables the use of supplimentary mobile networks like MMS, and HIPRI
while VPNs are running.

Change-Id: I313f57a905b4e16bd4322c68687cbff1cfbe9d3e

core/java/android/net/ConnectivityManager.java

@@ -479,6 +479,22 @@ public class ConnectivityManager {
         }
     }
 
+    /**
+     * Checks if the given network type should be exempt from VPN routing rules
+     *
+     * @hide
+     */
+    public static boolean isNetworkTypeExempt(int networkType) {
+        switch (networkType) {
+            case TYPE_MOBILE_MMS:
+            case TYPE_MOBILE_SUPL:
+            case TYPE_MOBILE_HIPRI:
+                return true;
+            default:
+                return false;
+        }
+    }
+
     /**
      * Specifies the preferred network type.  When the device has more
      * than one type available the preferred network type will be used.