Fix new Sonar smells; optimize some tests

spring-integration-kafka/src/test/java/org/springframework/integration/kafka/inbound/MessageSourceIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 the original author or authors.
+ * Copyright 2018-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -86,6 +86,9 @@ class MessageSourceIntegrationTests {
 			}
 
 		});
+
+		consumerProperties.setPollTimeout(10);
+
 		KafkaMessageSource<Integer, String> source = new KafkaMessageSource<>(consumerFactory, consumerProperties);
 
 		Map<String, Object> producerProps = KafkaTestUtils.producerProps(embeddedKafka);