Expose @KafkaListener BPP method handler factory

Allow external use of the framework's configured factory.

Author: garyrussell

spring-kafka/src/main/java/org/springframework/kafka/annotation/KafkaListenerAnnotationBeanPostProcessor.java

@@ -195,6 +195,15 @@ public void setMessageHandlerMethodFactory(MessageHandlerMethodFactory messageHa
 		this.messageHandlerMethodFactory.setHandlerMethodFactory(messageHandlerMethodFactory);
 	}
 
+	/**
+	 * Return the configured handler factory.
+	 * @return the factory.
+	 * @since 2.5.7
+	 */
+	public MessageHandlerMethodFactory getMessageHandlerMethodFactory() {
+		return this.messageHandlerMethodFactory;
+	}
+
 	/**
 	 * Making a {@link BeanFactory} available is optional; if not set,
 	 * {@link KafkaListenerConfigurer} beans won't get autodetected and an