Cherry-pick of PR #20989 to 7.x branch. Original message:

What does this PR do?

Kafka metricsets based on Jolokia require a different configuration to
the native metricsets. Disable the Jolokia ones by default, if someone
wants to use them, they need to explicitly enable and configure them.
Reference configuration contains information about this.

At the moment there is no way we can provide default metricsets in the
same module that need different hosts configurations.

In any case consumer and producer metricsets are intended to monitor
Java consumers and producers, while the rest of metricsets are intended
to monitor Kafka brokers. So there is little chance that all of them are going
to be enabled in the same configuration.

Why is it important?

To avoid errors with default configuration.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Errors seen in this discuss topic: https://discuss.elastic.co/t/kafka-monitoring-in-kubernetes/247527/3

Use cases

Using the kafka module, without specifying defaults, should provide a working configuration.

Logs

Errors like these ones appear when using default configuration:

Error fetching data for metricset kafka.broker: error making http request: Post "http://pipeline-kafka:9092/jolokia/%3FignoreErrors=true&canonicalNaming=false": read tcp 10.5.7.136:34466->172.20.79.178:9092: read: connection reset by peer
Error fetching data for metricset kafka.producer: error making http request: Post "http://pipeline-kafka:9092/jolokia/%3FignoreErrors=true&canonicalNaming=false": read tcp 10.5.7.136:34470->172.20.79.178:9092: read: connection reset by peer

Metricbeat tries to request jolokia metrics from the Kafka endpoint.