Upgrade compatibility of Zookeeper to 3.7

[sayden]

The Zookeeper integration is going to be upgraded here elastic/beats#30068 to 3.7 so the integration must reflect those changes too.

• Blocked by ZooKeeper module: Adapt to ZooKeeper 3.6+ mntr response fields' changes. beats#30068

[elasticmachine]

Pinging @elastic/integrations (Team:Integrations)

[botelastic]

Hi! We just realized that we haven't looked into this issue in a while. We're sorry! We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1. Thank you for your contribution!