
The goal is to simplify the os_horizon role by dropping out an unnecessary step of Keystone role creation, when a non-default value is set for `horizon_default_role_name`. In case a deployer needs to have a non-default value for horizon_default_role_name, they are encouraged to leverage an openstack_resources role/playbook to provision such role for them. Change-Id: I97d3c837a880c0ce3ebf6c44d94e85e4e9e52b23