Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1931316

Description of problem:

We have this in the default kickstart template:

bootloader --location=mbr --append="<%= host_param('bootloader-append') || 'nofb quiet splash=quiet' >" <= @grub_pass %>

According to https://community.theforeman.org/t/grub-pass-ks-console/10610, @grub_pass is defined nowhere and the code is dead. Thus, we should change the template to use @host.grub_pass so that people can define grub_grass as a host/hg/global param.

Version-Release number of selected component (if applicable):

6.8

How reproducible:

Easy

Steps to Reproduce:
1. nowhere to define @grub_pass. The only way to change the booloader password is to clone the template. However, in same cases, people do not want to clone.

Actual results:

Can not define @grub_pass to pass the bootloader password

Expected results:

Can define @grub_pass to pass the password.