title: Acknowledgement.acknowledge() throwing exception in spring-kafka @KafkaListener
body: <p>When I set enable.auto.commit to false and try to manually commit offset using annotation based spring-kafka @KafkaListener, I get a <strong>org.springframework.kafka.listener.ListenerExecutionFailedException: Listener method could not be invoked with the incoming message</strong></p>
  
  <p>I have a very simple code as follows:</p>
  
  <pre><code>@KafkaListener(id = "someid", topics = "${demo.topic}", containerFactory = "someContainerFactory")
  public void listenFooGroup(String message, Acknowledgement ack) {
      System.out.println("Received Messasge in group 'foo': " + message);
  
      // TODO: Do something with the message
  }
  </code></pre>
  
  <p>And when I send a message from the producer, I get the following exception:</p>
  
  <p>org.springframework.kafka.listener.ListenerExecutionFailedException: Listener method could not be invoked with the incoming message.</p>
  
  <p>Endpoint handler details:</p>
  
  <p>Method [public void com.****.*****.*******.KafkaMessageListener.listenFooGroup(java.lang.String,org.springframework.kafka.support.Acknowledgment)]</p>
  
  <blockquote>
    <p>Bean [com.****.*****.*******.KafkaMessageListener@5856dbe4]; nested exception is org.springframework.messaging.converter.MessageConversionException: Cannot handle message; nested exception is org.springframework.messaging.converter.MessageConversionException: Cannot convert from [java.lang.String] to [org.springframework.kafka.support.Acknowledgment] for GenericMessage [payload=test, headers={kafka_offset=57, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, kafka_receivedTopic=demotopic}],
    failedMessage=GenericMessage [payload=test, headers={kafka_offset=57, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, kafka_receivedTopic=demotopic}]</p>
  </blockquote>
  
  <p>Please help. TIA.</p>