[Fleet] Support dimension mappings in dynamic templates

[jsoriano]

Summary

Add time_series_dimension: true to dynamic field mappings defined with dimension: true.

Fixes #179649.

Related to elastic/elasticsearch#93564.

Checklist

• Unit or functional tests were updated or added to match the most common scenarios

Risk Matrix

Risk	Probability	Severity	Mitigation/Notes
Sets of dimensions change after upgrading package	Low (no package is using this now?)	Medium	Add knowledge base issue about this. Package maintainers may need to analyze the possible migration path for these packages. @lalit-satapathy @tetianakravchenko please confirm if this can be an issue.

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[apmmachine]

🤖 GitHub comments

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Just comment with:

• /oblt-deploy : Deploy a Kibana instance using the Observability test environments.
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[juliaElastic]

LGTM

[kibana-ci]

💚 Build Succeeded

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• Commit: 6968df8

Metrics [docs]

✅ unchanged

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@elasticmachine merge upstream

cc @jsoriano