Comment 7 for bug 1952353

I can now see that the dmesg command - starting with Ubuntu 21.10 - is NOT meant to work for the users in "adm" group. It is now meant to be run as admin or with sudo. This is a security decision.
Described in here: https://ruffell.nz/programming/writeups/2020/10/24/getting-dmesg-restrict-enabled-in-ubuntu-groovy.html