Allow to customize faillock config

[snowsky]

Adding faillock.conf file into writable-paths to be able to customize faillock config.
Will put up a PR to core-base after this is approved.

[snowsky]

Test case phase failed at the setup step:

--2023-04-11 15:53:55--  http://cdimage.ubuntu.com/ubuntu-base/focal/daily/current/focal-base-amd64.tar.gz
Resolving cdimage.ubuntu.com (cdimage.ubuntu.com)... 185.125.190.37, 185.125.190.40, 91.189.91.124, ...
Connecting to cdimage.ubuntu.com (cdimage.ubuntu.com)|185.125.190.37|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2023-04-11 15:53:55 ERROR 404: Not Found.

The file doesn't exist on Ubuntu website, http://cdimage.ubuntu.com/ubuntu-base/focal/daily/current/focal-base-amd64.tar.gz.

[snowsky]

Hi @valentindavid, do you think this is good for approval? Thanks :)