There's no default kickstart installation mode in osbuild-base.ks.

# cat /mnt/osbuild-base.ks 
ostreecontainer --url=/run/install/repo/container --transport=oci --no-signature-verification
rootpw --lock
lang en_US.UTF-8
keyboard us
timezone UTC
clearpart --all
network --device=link --bootproto=dhcp --onboot=on --activate 

According to https://docs.centos.org/en-US/8-docs/advanced-install/assembly_kickstart-commands-and-options-reference/#text_kickstart-commands-for-installation-program-configuration-and-flow-control, for a fully automatic installation, you must either specify one of the available modes (graphical, text, or cmdline) in the Kickstart file.

The automatic installation is not supported by virt-install on aarch64.

I think we should have a default mode, graphical or text to make the ISO automatic installation. Customer can replace kickstart file by themselves if they need.