Add interface name for proxy network type.

This will make test
android.net.cts.ConnectivityManagerTest#testRequestRouteToHost pass.
Change-Id: I5a14b6d705e87018e1e2c031aaacee533536a50b

Bug: 15320910
diff --git a/core/java/android/net/ProxyDataTracker.java b/core/java/android/net/ProxyDataTracker.java
index 461e8b8..3eebef9 100644
--- a/core/java/android/net/ProxyDataTracker.java
+++ b/core/java/android/net/ProxyDataTracker.java
@@ -48,6 +48,7 @@
     // TODO: investigate how to get these DNS addresses from the system.
     private static final String DNS1 = "8.8.8.8";
     private static final String DNS2 = "8.8.4.4";
+    private static final String INTERFACE_NAME = "ifb0";
     private static final String REASON_ENABLED = "enabled";
     private static final String REASON_DISABLED = "disabled";
     private static final String REASON_PROXY_DOWN = "proxy_down";
@@ -107,10 +108,11 @@
         mLinkCapabilities = new LinkCapabilities();
         mNetworkInfo.setIsAvailable(true);
         try {
-          mLinkProperties.addDns(InetAddress.getByName(DNS1));
-          mLinkProperties.addDns(InetAddress.getByName(DNS2));
+            mLinkProperties.addDns(InetAddress.getByName(DNS1));
+            mLinkProperties.addDns(InetAddress.getByName(DNS2));
+            mLinkProperties.setInterfaceName(INTERFACE_NAME);
         } catch (UnknownHostException e) {
-          Log.e(TAG, "Could not add DNS address", e);
+            Log.e(TAG, "Could not add DNS address", e);
         }
     }