Description of problem:

FQDN hieradata is hardcoded.

With the move to composable networks, most of the network-related bits are now dynamically generated with jinja. The only exception seems to be the FQDN hieradata keys, which still are hardcoded.

Which means that nay service that uses the FQDN hiera keys depending on the network will fail to do so on a custom network.

Version-Release number of selected component (if applicable):
OSP12

How reproducible:
100%

Steps to Reproduce:
1. Deploy the overcloud with a custom network (by modifying roles_data.yaml and network_data.yaml)
2. verify the fqdn_* hiera keys.

Actual results:
fqdn_* hiera keys are not generated for the custom network(s)

Expected results:
They should be generated.

Additional info: