Description of problem:
The network panel of the Anaconda GUI allows to create a bridged VLAN interface. The resulting ifcfg files looks good, but the resulting anaconda-ks.cfg doesn't allow to reproduce the network configuration.

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


How reproducible:


Steps to Reproduce:
1. Use the following kickstart directive (supposing ens3 is your parent device)
network  --bootproto=dhcp --device=bridge0 --ipv6=auto --bridgeslaves=ens3.100 --bridgeopts=priority=32768,stp=yes --no-activate
network  --bootproto=dhcp --device=ens3 --onboot=off --ipv6=auto --activate
network  --hostname=localhost.localdomain

2. Install a minimal server with this kickstart.

3. Observe the garbage connection which is created (not a VLAN and not enslaved)


Actual results:
# cat ifcfg-bridge0_slave_1
# Generated by parse-kickstart
TYPE="Ethernet"
NAME="bridge0 slave 1"
UUID="db232faa-7741-42af-a047-2b16fd91a44e"
ONBOOT="yes"
BRIDGE="bridge0"
DEVICE="eth0.100"

# ls /sys/class/net/bridge0/brif
==> nothing enslaved

Expected results:
# nmcli con show
NAME                 UUID                                  TYPE      DEVICE   
bridge0 slave 1      a98a9142-cffe-4100-81d2-c5bc4a7e18e0  vlan      eth0.100 
eth0                 d281553e-a52b-4254-9adc-f0390eea1098  ethernet  eth0     
Bridge connection 1  2c0aaf4c-a77f-4fce-a1e6-73ada5e53153  bridge    bridge0  

# ls /sys/class/net/bridge0/brif
eth0.100


Additional info:
This bug is a clone for https://bugzilla.redhat.com/show_bug.cgi?id=1731190
The same issue occurs on RHEL 8. More information like the anaconda logs are attached to this one.