title: Make Kafka Consumer wait for Events
body: <p>I have a use case where a consumer needs to listen to some events on a topic T1(consumesmessages in topic T1 and search for certain cases) .Only if it detect certain events then start consuming from topic T2 and  work on the messages retrieved from T2.We are using spring kafka 2.1.7.I do not see a way to do this now
  as consumer would start reading from T2 as  the kafkalistener  bean for it comes up .I am looking for suggestions on how this can be achieved.</p>