Extend the logs-*-* index template with this:

 "composed_of": [ "logs-mappings", "data-streams-mappings", "logs-settings", "logs@custom" ], "ignore_missing_component_templates": ["logs@custom"], 

The effect of this is that if a user is not happy with our changes, they can created the logs@custom component template and overwrite it. Because of the ignore_missing, the template does not have to exist.

We'll need to test what happens if a user creates this component template and tries to override a setting that we have also configured in logs-settings. For example, setting ignore_malformed to false. Ideally, the user setting should take precedence then.