nixos/kmscon: use upstream service file

  };

  config = mkIf cfg.enable {

    # Largely copied from unit provided with kmscon source

    systemd.units."kmsconvt@.service".text = ''

      [Unit]

      Description=KMS System Console on %I

      Documentation=man:kmscon(1)

      After=systemd-user-sessions.service

      After=plymouth-quit-wait.service

      After=systemd-logind.service

      After=systemd-vconsole-setup.service

      Requires=systemd-logind.service

      Before=getty.target

      Conflicts=getty@%i.service

      OnFailure=getty@%i.service

      IgnoreOnIsolate=yes

      ConditionPathExists=/dev/tty0

      [Service]

      ExecStart=

      ExecStart=${pkgs.kmscon}/bin/kmscon "--vt=%I" ${cfg.extraOptions} --seats=seat0 --no-switchvt --configdir ${configDir} --login -- ${pkgs.shadow}/bin/login -p ${autologinArg}

      UtmpIdentifier=%I

      TTYPath=/dev/%I

      TTYReset=yes

      TTYVHangup=yes

      TTYVTDisallocate=yes

      X-RestartIfChanged=false

    '';

    systemd.packages = [ pkgs.kmscon ];

    systemd.services."kmsconvt@" = {

      after = [ "systemd-logind.service" "systemd-vconsole-setup.service" ];

      requires = [ "systemd-logind.service" ];

      serviceConfig.ExecStart = [

        ""

        ''

          ${pkgs.kmscon}/bin/kmscon "--vt=%I" ${cfg.extraOptions} --seats=seat0 --no-switchvt --configdir ${configDir} --login -- ${pkgs.shadow}/bin/login -p ${autologinArg}

        ''

      ];

      restartIfChanged = false;

      aliases = [ "autovt@.service" ];

    };

    systemd.suppressedSystemUnits = [ "autovt@.service" ];

    systemd.units."kmsconvt@.service".aliases = [ "autovt@.service" ];

    systemd.services.systemd-vconsole-setup.enable = false;

    systemd.services.reload-systemd-vconsole-setup.enable = false;