Fix Javadoc for ListenerContainerFactoryConfigurer

Remove outdated comments in ListenerContainerFactoryConfigurer

Fix unused import

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/ListenerContainerFactoryConfigurer.java

@@ -28,7 +28,6 @@
 import org.springframework.kafka.config.KafkaListenerEndpoint;
 import org.springframework.kafka.listener.CommonErrorHandler;
 import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
-import org.springframework.kafka.listener.ContainerProperties;
 import org.springframework.kafka.listener.ContainerProperties.AckMode;
 import org.springframework.kafka.listener.DeadLetterPublishingRecoverer;
 import org.springframework.kafka.listener.DefaultErrorHandler;
@@ -46,10 +45,6 @@
  * {@link DefaultErrorHandler} and the {@link DeadLetterPublishingRecoverer}
  * created by the {@link DeadLetterPublishingRecovererFactory}.
  *
- * Also sets {@link ContainerProperties#setIdlePartitionEventInterval(Long)}
- * and {@link ContainerProperties#setPollTimeout(long)} if its defaults haven't
- * been overridden by the user.
- *
  * Since 2.8.3 these configurations don't interfere with the provided factory
  * instance itself, so the same factory instance can be shared among retryable and
  * non-retryable endpoints.