PolicyKit rules never come into effect
If you are on Ubuntu 19.04 (or lower) then you are still using the old version of PolKit, where there are no .rules files but only .pkla and .conf files.
On the command prompt, do:
pkaction --version
If it says < 0.106, then you can only use the old syntax.
You can create a .pkla file in /etc/polkit-1/localauthority/