Fix delay timeout in MockTransportService (#97336) (#97338)

We can pass an invalid duration to TimeValue, which accepts either -1 or
an non-negative duration.

test/framework/src/main/java/org/elasticsearch/test/transport/MockTransportService.java

@@ -404,9 +404,12 @@ public void addUnresponsiveRule(TransportService transportService, final TimeVal
      * @param duration the amount of time to delay sending and connecting.
      */
     public void addUnresponsiveRule(TransportAddress transportAddress, final TimeValue duration) {
-        final long startTime = System.currentTimeMillis();
+        final long startTimeInMillis = threadPool.relativeTimeInMillis();
 
-        Supplier<TimeValue> delaySupplier = () -> new TimeValue(duration.millis() - (System.currentTimeMillis() - startTime));
+        Supplier<TimeValue> delaySupplier = () -> {
+            long elapsed = threadPool.relativeTimeInMillis() - startTimeInMillis;
+            return new TimeValue(Math.max(duration.millis() - elapsed, 0));
+        };
 
         transport().addConnectBehavior(transportAddress, new StubbableTransport.OpenConnectionBehavior() {
             private CountDownLatch stopLatch = new CountDownLatch(1);