On previous commit missed "default=''" so changing:
project_domain_name=cred.get_input('project_domain_name'))
to
project_domain_name=cred.get_input('project_domain_name', default=''))
Keystone v3 requires user_domain_id and project_domain_name to authenticate, but AWX openstack credential only requests the user_domain_id.
Added in project_domain_name into the credential templating. Not added as a required field as this is only needed when using Keystone v3.