Fix the 3rd test

Signed-off-by: david_radley@uk.ibm.com <david_radley@uk.ibm.com>

Author: davidradl

flink-runtime/src/test/java/org/apache/flink/runtime/scheduler/slowtaskdetector/ExecutionTimeBasedSlowTaskDetectorTest.java

@@ -480,13 +480,13 @@ private ExecutionGraph createExecutionGraph(JobVertex... jobVertices) throws Exc
                 (jobId, newJobStatus, timestamp) -> {
                     if (newJobStatus == JobStatus.RUNNING) {
                         // Only complete the future when all vertices are in RUNNING state
-                        long runningCount =
-                                executionGraph.getAllExecutionVertices().stream()
-                                        .filter(
-                                                v ->
-                                                        v.getCurrentExecutionAttempt().getState()
-                                                                == ExecutionState.RUNNING)
-                                        .count();
+                        long runningCount = 0;
+                        for (ExecutionVertex vertex : executionGraph.getAllExecutionVertices()) {
+                            if (vertex.getCurrentExecutionAttempt().getState()
+                                    == ExecutionState.RUNNING) {
+                                runningCount++;
+                            }
+                        }
                         if (runningCount >= expectedVertexCount) {
                             allVerticesRunningFuture.complete(null);
                         }