CAMEL-23901: Fix flaky MulticastParallelStreamingTimeoutTest (#24417)

* CAMEL-23901: Fix flaky MulticastParallelStreamingTimeoutTest

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Guillaume Nodet <gnodet@gmail.com>

* CAMEL-23901: Set short resultWaitTime to avoid double-wait with Awaitility

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Guillaume Nodet <gnodet@gmail.com>

---------

Signed-off-by: Guillaume Nodet <gnodet@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: gnodet

core/camel-core/src/test/java/org/apache/camel/processor/MulticastParallelStreamingTimeoutTest.java

@@ -16,28 +16,40 @@
  */
 package org.apache.camel.processor;
 
+import java.util.concurrent.TimeUnit;
+
 import org.apache.camel.AggregationStrategy;
 import org.apache.camel.ContextTestSupport;
 import org.apache.camel.Exchange;
 import org.apache.camel.builder.RouteBuilder;
 import org.apache.camel.component.mock.MockEndpoint;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.DisabledOnOs;
+import org.junit.jupiter.api.parallel.Isolated;
+
+import static org.awaitility.Awaitility.await;
 
+@Isolated("Short timeouts cause problems with parallel test execution")
 @DisabledOnOs(architectures = { "s390x" },
               disabledReason = "This test does not run reliably on s390x (see CAMEL-21438)")
 public class MulticastParallelStreamingTimeoutTest extends ContextTestSupport {
 
     @Test
     public void testMulticastParallelStreamingTimeout() throws Exception {
         MockEndpoint mock = getMockEndpoint("mock:result");
-        // A will timeout so we only get B and C (C is faster than B)
-        mock.expectedBodiesReceived("CB");
-        mock.setResultWaitTime(20000);
+        // A will timeout so we only get B and C (order may vary)
+        mock.expectedMessageCount(1);
+        mock.message(0).body().not(body().contains("A"));
+        mock.message(0).body().contains("B");
+        mock.message(0).body().contains("C");
+        // Use a short result wait time so each Awaitility attempt checks quickly
+        // without blocking (default 0 maps to 10s internally in MockEndpoint)
+        mock.setResultWaitTime(100);
 
         template.sendBody("direct:start", "Hello");
 
-        assertMockEndpointsSatisfied();
+        await().atMost(20, TimeUnit.SECONDS)
+                .untilAsserted(() -> assertMockEndpointsSatisfied());
     }
 
     @Override