Please review fips gadget

[xnox]

https://github.com/snapcore/pc-gadget/compare/22...22-fips?expand=1

Given it is not quite possible to generate a pull request without any shared history, I directly pushed this initial fips gadget packaging.

It currently stages existing gadget, and adds extra cmdline argument fips=1. I hope in the future to remove the extra cmdline argument. However 22-fips tracks will remain, to be able to control releases of gadgets w.r.t. signing keys used by kernel snaps.

[alfonsosanchezbeato]

You could have created an empty commit, push that to 22-fips and created a PR to it, I believe. Anyway, this is fine.

Could not we just use plugin: nil instead of dump?

Otherwise LGTM, although note that in the near future we are going to have an "append" to kernel command line option in gadget.yaml, so the cmdline.extra file will not be necessary anymore.

[xnox]

Could not we just use plugin: nil instead of dump?

I need it to stage the cmdline.extra file, cause with plugin:nil it doesn't exist.