Code review comment for ~smoser/cloud-init:bug/1683038-ec2-no-warn-on-explicit

I think that the signature change is fine.
the other fixme I think is best fixed by just having ds-identify write an entry in the config that says that it wrote a datasource_list, and how it did that.

Ie, it could declare that it essentially copied the datasource list like this:
   di_datasource_list_method: copy

or something to that affect. Then cloud-init could read that. A 'copy' there would be different than 'search'. The copy would show no warning, but the search would.

I'm not sure stil..
We *should* grab the other parts of this merge proposal and get them into main.