MMS proxy host dns lookup should happen on mms network

b/24071236

Change-Id: Ia34a66ce1a09276dab4e98b8ee0ab0fa819eea65
diff --git a/src/com/android/mms/service/MmsHttpClient.java b/src/com/android/mms/service/MmsHttpClient.java
index e09695c..f6d3d1b 100644
--- a/src/com/android/mms/service/MmsHttpClient.java
+++ b/src/com/android/mms/service/MmsHttpClient.java
@@ -109,7 +109,8 @@
         try {
             Proxy proxy = Proxy.NO_PROXY;
             if (isProxySet) {
-                proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));
+                proxy = new Proxy(Proxy.Type.HTTP,
+                        new InetSocketAddress(mNetwork.getByName(proxyHost), proxyPort));
             }
             final URL url = new URL(urlString);
             // Now get the connection