Disable systemd-modules-load.service inside planet

[knisbet]

Description

What happened: On a customer cluster they noticed after a reboot a gravity status alert for the systemd-modules-load service inside planet. We don't use the service, so it should probably just be masked / disabled.

Inside Planet:

kevin-test1:/$ systemctl list-units 'systemd-modules-load.service'
UNIT                         LOAD   ACTIVE SUB    DESCRIPTION
systemd-modules-load.service loaded active exited Load Kernel Modules

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

1 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

[knisbet]

At the same time:

• should mask the systemd-rfkill.socket / systemd-rfkill.service since they're not used
• mask any other services / sockets / resources systemd adds by default that we don't use.