Fix shadowing in tests. Constructor and method are not allowed to have

tests/standalone/io/echo_server_stream_test.dart

Index: tests/standalone/io/echo_server_stream_test.dart
diff --git a/tests/standalone/io/echo_server_stream_test.dart b/tests/standalone/io/echo_server_stream_test.dart
index 8edcffbf9049a222c31b6d1d1ec1224ac68390a3..505abc42db16e82611e1231f56512f4bf4c59e95 100644
--- a/tests/standalone/io/echo_server_stream_test.dart
+++ b/tests/standalone/io/echo_server_stream_test.dart
@@ -28,7 +28,7 @@ class EchoServerGame {
       _buffer[i] = FIRSTCHAR + i;
     }
     _sendPort = spawnFunction(startEchoServer);
-    start();
+    initialize();
   }
 
   void sendData() {
@@ -111,7 +111,7 @@ class EchoServerGame {
     }
   }
 
-  void start() {
+  void initialize() {
     _receivePort.receive((var message, SendPort replyTo) {
       _port = message;
       sendData();