Snippet `redhat_register` try to install subscription-manager (at about line 115).

On an air-gapped infrastructure, that causes a timeout trying reach an unreachable internet repo.

It slows down the kickstart then if subscription-manager has not been installed before, I guess some part of the kickstart will failed.

I do install subscription-manager in the custom snippet of section %packages because I think it's the only place I can do that.

Then it would be nice to speed-up an air gapped kickstart by avoiding to wait for an inevitable timeout.