Updated the discovery mojom.

Change-Id: Ia29310f8b702f017dff68f3c57b0ad3110554299
diff --git a/mojom/v.io/x/ref/services/discovery/discovery.mojom b/mojom/v.io/x/ref/services/discovery/discovery.mojom
index 3b1080e..17b5146 100644
--- a/mojom/v.io/x/ref/services/discovery/discovery.mojom
+++ b/mojom/v.io/x/ref/services/discovery/discovery.mojom
@@ -19,9 +19,9 @@
 };
 
 struct Service {
-	// The service types that this service implements
+	// The interface name this service implements.
 	// E.g. 'v.io/v23/Display.T
-	array<string> InterfaceNames;
+	string InterfaceNames;
 
 	map<string, string> Attrs;