This is something I actually like about systemd and firewalld, everything in /usr/lib/systemd/ and /usr/lib/firewalld should only be handled by your package man

This is something I actually like about systemd and firewalld, everything in /usr/lib/systemd/ and /usr/lib/firewalld should only be handled by your package manager, anything you customize yourself belongs in /etc/systemd/ and /etc/firewalld, and they will override the corresponding entries in the 'global' folders if you give them the same filename.