Description of problem:
As of https://bugzilla.redhat.com/show_bug.cgi?id=1189813, the cloud-init
integration with ovirt supports just a sub-set of cloud-init keys.

The following template seems to be the maximal set of keys we
can currently pass successfully to the cloud-init via user_data:

```
#cloud-init
hostname: test.example.com
ssh_authorized_keys:
- ssh-rsa test123123123 test.example.com
runcmd:
- ls /
phone_home:
  url: satellite.example.com
  post: []
```

Cloud-init supports much wider range or modules and configuration options,
https://cloudinit.readthedocs.io/en/latest/topics/modules.html#. Currently
we don't support those and this options get ignored.

Version-Release number of selected component (if applicable):
6.3.0

How reproducible:
Always

Steps to Reproduce:
1. add user_data image with cloud-init installed and configured.
2. use one of the valid cloud-init keys that ARE NOT one of `hostname`, `ssh_authorized_keys`, `runcmd`, `phone_home`,
an example could be:
```
#cloud-init
yum_repos:
    zoo:
        baseurl: https://inecas.fedorapeople.org/fakerepos/new_cds/content/zoo/1.0/x86_64/rpms/
        name: zoo
        enabled: true
```



Actual results:
Many cloud-init modules options get ignored (including the `yum_repos` one in the example)

Expected results:
All cloud-init modules options get passed to cloud-init (including the `yum_repos` one in the example)

Additional info: