ironic_adoption: fix Jinja2 rendering

Jinja2 stripping whitespace/linebreak issue, the CR was rendered as:
```
      customServiceConfig: |
        [DEFAULT]
        default_network_interface=neutron      ironicAPI:
        replicas: 1
```

Which cause invalid config, and ironic-conductor to never start.

Jira: OSPRH-20021
Signed-off-by: Harald Jensås <hjensas@redhat.com>

Author: hjensas

tests/roles/ironic_adoption/defaults/main.yaml

@@ -16,11 +16,7 @@ ironic_patch: |
         databaseInstance: openstack
         customServiceConfig: |
           [DEFAULT]
-          {% if ipv6_enabled | default(false) -%}
-          default_network_interface=neutron
-          {%- else -%}
-          default_network_interface=flat
-          {%- endif %}
+          default_network_interface={{ 'neutron' if ipv6_enabled | default(false) else 'flat' }}
         ironicAPI:
           replicas: 1
           override: