Add tsdb metrics builtin component template

[martijnvg]

Fleet is currently hard coded to set index.codec to best_compression (deflate compression). This is good for most data streams, except for data streams were tsdb is enabled. Ideally Fleet doesn't need to set this setting at all and Elasticsearch's default would be good. But unfortunately this isn't the case. It default to default (lz4 - optimised for speed), which in would mean much higher disk space usage. Ideally the default would be default when synthetic source is enabled and otherwise best_compression. Changing this now, would mean a breaking change.

Instead Fleet like to depend on Elasticsearch's internal component templates. To at least abstract some of the internal details away. The metrics-settings is ok for non tsdb, but there is no component template for tsdb metrics. This PR adds this.

Relates to elastic/kibana#160288

[github-actions]

Documentation preview:

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[elasticsearchmachine]

Hi @martijnvg, I've created a changelog YAML for you.

[felixbarny]

You'll probably need to update

elasticsearch/test/framework/src/main/java/org/elasticsearch/test/rest/ESRestTestCase.java

Line 1842 in 5ebfdda

case "metrics-settings":

And add metrics-tsdb-settings.

Otherwise LGTM

[elasticsearchmachine]

Pinging @elastic/es-analytics-geo (Team:Analytics)

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[martijnvg]

@elasticmachine update branch

[ruflin]

@eyalkoren New built in template here. Can you check that it aligns with the naming convention?

[eyalkoren]

@eyalkoren New built in template here. Can you check that it aligns with the naming convention?

Is there a naming convention already? 🤔

[ruflin]

Lets align it with the hopefully soon to be reached conclusion in #96267

[andreidan]

LGTM, thanks Martijn

[andreidan]

Just a reminder to override this in stateless to use data stream lifecycle (assuming this component template will be used in data streams only)

[martijnvg]

iirc this will be used with data streams.