[plugin installer] check multiple default paths for config

[jbudz]

With #7275 packages install their config to /etc/kibana/kibana.yml by default. This updates the plugin installer to check multiple default paths, and adds the package path to the list.

[jbudz]

jenkins, test it

[BigFunger]

Wouldn't using _.find() make more sense than _.some() here? They both iterate through a collection and stop once a condition is met, but... some is used to answer a question about the state of a collection; "Are there some elements in the collection that meet these conditions?" Where find is used to return an element in a collection; "Give me the first element of a collection that meets these conditions"

[LeeDr]

Are we checking multiple paths for kibana.yml to cover both the cases of package installation and archive installation?

• for a package install we create and use /etc/kibana/kibana.yml
• for users who just unzip or untar the archive fromRoot('config/kibana.yml')?

Or are we trying to handle an upgrade case without having to move the previous version kibana.yml?

[jbudz]

@LeeDr checking multiple paths for package and archive installation.

[epixa]

This seems like it needs to be a blocker since #7308 is merged. Otherwise plugin install will fail on package installs, right?

Edit: fixed PR link

[epixa]

If #7308 ends up getting backported, make sure this does as well.

[jbudz]

Correct, it'll fail unless -c /etc/kibana/kibana.yml is specified

[BigFunger]

LGTM