Index management errors messages should always specify the correct index management type to use

[cmacknz]

This is follow up from #36649

If you run filebeat setup --index-management with the default parameters where both setup.ilm.overwrite: false and setup.dsl.overwrite: false are set against either a serverless project or stateful deployment you will get the following error:

Overwriting lifecycle policy is disabled. Set `setup.ilm.overwrite: true` or `setup.dsl.overwrite: true` to overwrite.
Index setup finished.

This error is expected, but the error message should tell the user which of ilm or dsl to use since the Beat knows which one is correct. This error message is generated with the default parameters so we should be as explicit as possible, since this is probably the first message a user will ever see when trying to use index management in Beats for the first time.

Specifically, when connected to a stateful deployment the error message should be:

Overwriting ILM policy is disabled. Set `setup.ilm.overwrite: true` to overwrite.

When connected to a serverless project the error message should be:

Overwriting DSL policy is disabled. Set `setup.dsl.overwrite: true` to overwrite.