Make the Dart application library code stop using the "wrong way" service provider (a.k.a. exposed_…

mojo/dart/apptests/test_apps/echo/lib/main.dart

Index: mojo/dart/apptests/test_apps/echo/lib/main.dart
diff --git a/mojo/dart/apptests/test_apps/echo/lib/main.dart b/mojo/dart/apptests/test_apps/echo/lib/main.dart
index 4ace20ac1e70d7281482d1051c7bd2c6d68358c0..76ad19668b33036fc92569476b3dba9bc56dcd9a 100644
--- a/mojo/dart/apptests/test_apps/echo/lib/main.dart
+++ b/mojo/dart/apptests/test_apps/echo/lib/main.dart
@@ -57,8 +57,6 @@ class EchoApplication extends Application {
   @override
   void acceptConnection(String requestorUrl, String resolvedUrl,
       ApplicationConnection connection) {
-    // No services are required from the remote end.
-    connection.remoteServiceProvider.close();
     connection.provideService(EchoService.serviceName,
         (endpoint) => new EchoServiceImpl(this, endpoint));
   }