Improve DelayerUsageTests

The time-based tests are very sensitive to an activity on the target machine.
So, strict test sometimes fail.

* Fix `DelayerUsageTests` to deal with approximate values to compare by some percentage

spring-integration-core/src/test/java/org/springframework/integration/config/xml/DelayerUsageTests.java

@@ -80,7 +80,7 @@ public class DelayerUsageTests {
 				});
 
 		assertThat(outputA.receive(10000)).isNotNull();
-		assertThat(System.currentTimeMillis() - start).isGreaterThanOrEqualTo(1000);
+		assertThat(System.currentTimeMillis() - start).isCloseTo(1000, withinPercentage(10));
 	}
 
 	@Test
@@ -124,17 +124,17 @@ public class DelayerUsageTests {
 		delayerInsideChain.send(new GenericMessage<>("Hello"));
 		Message<?> message = outputA.receive(10000);
 		assertThat(message).isNotNull();
-		assertThat(System.currentTimeMillis() - start).isGreaterThanOrEqualTo(1000);
+		assertThat(System.currentTimeMillis() - start).isCloseTo(1000, withinPercentage(10));
 		assertThat(message.getPayload()).isEqualTo("hello");
 	}
 
 	@Test
-	public void testInt2243DelayerExpression() {
+	public void delayEvaluatedFromExpression() {
 		long start = System.currentTimeMillis();
 		this.inputC.send(new GenericMessage<>("test"));
 		Message<?> message = this.outputC.receive(10000);
 		assertThat(message).isNotNull();
-		assertThat(System.currentTimeMillis() - start).isGreaterThanOrEqualTo(1000);
+		assertThat(System.currentTimeMillis() - start).isCloseTo(1000, withinPercentage(10));
 		assertThat(message.getPayload()).isEqualTo("test");
 	}