Add Kafka Indexing Service metrics to emitter whitelists

### Description

As the Kafka Indexing Service has been promoted out of experimental, it would be nice to include its metrics in the emitter whitelists, example [StatsD](https://github.com/apache/incubator-druid/blob/master/extensions-contrib/statsd-emitter/src/main/resources/defaultMetricDimensions.json).

### Motivation

With KIS out of experimental it makes sense to include the metrics it exposes in any set of whitelisted published metrics.

If this isn't something that's wanted, then I would like to see all the metrics published by KIS listed out in its docs so that people (me) don't need to hunt around for them. This would be a good thing to do anyway, to be fair.

Start with extensions-contrib/statsd-emitter/src/main/resources/defaultMetricDimensions.json and identify the Kafka Indexing Service metrics that are currently exposed. Check the other emitter whitelists and the KIS documentation mentioned in the issue; done means the relevant whitelists include those metrics, or the complete KIS metric list is documented.

Written by the indexing model from the issue text.