fix: fix TCK failure (#153)

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Fixes #<issue_number_goes_here> 🦕

Author: kabir

sdk-server-common/src/main/java/io/a2a/server/requesthandlers/DefaultRequestHandler.java

@@ -162,8 +162,9 @@ public EventKind onMessageSend(MessageSendParams params) throws JSONRPCError {
         ResultAggregator.EventTypeAndInterrupt etai = null;
         try {
             EventConsumer consumer = new EventConsumer(queue);
-            etai = resultAggregator.consumeAndBreakOnInterrupt(consumer);
             producerRunnable.addDoneCallback(consumer.createAgentRunnableDoneCallback());
+            etai = resultAggregator.consumeAndBreakOnInterrupt(consumer);
+            
             if (etai == null) {
                 log.debug("No result, throwing InternalError");
                 throw new InternalError("No result");