Simplify Debian/Ubuntu OS family matching

Summary:
Instead to target Debian and Ubuntu individually, we use os_family.

For the BitchX exception, we left as is: nothing forbids to add it to
one distro independently of the other.

Test Plan: Retry state, assert it's no-op

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D963