Description of problem:

RFE SAT-18360 adds new parameter `foreman-ipa-sssd-default-realm` to the `satellite-installer` utility.
Doc for this param needs to be added to the CLI help page.

How reproducible:

100%

Is this issue a regression from an earlier version:

no

Steps to Reproduce:

1. Check the installer CLI help page for the new parameter:

satellite-installer --help 2>&1 | grep foreman-ipa-sssd-default-realm || echo "Nothing here"

Actual behavior:
"Nothing here"

Expected behavior:
Brief description of the `foreman-ipa-sssd-default-realm` parameter.

Business Impact / Additional info: