nixos/modules/misc/polkit.nix

{ config, ... }:
{
  security.polkit.enable = true;
  security.polkit.extraConfig = ''
    polkit.addRule(function(action, subject) {
      if ((action.id == "org.xfce.thunar" ||
        action.id == "org.freedesktop.policykit.exec" ||
        action.id == "org.gnome.gparted" ||
        action.id == "org.freedesktop.udisks2.encrypted-unlock-system" ||
        action.id == "org.freedesktop.udisks2.filesystem-mount-system") &&
        subject.isInGroup("wheel"))
      {
        return polkit.Result.YES;
      }
    });
  '';
}