At present, if openrc_system_scope is enabled, the default
value in clouds.yaml is also modified. This can negatively
impact some OSA tasks like openstack_resources which mostly
require project scope.
This patch adds an extra variable which can be used to override
the clouds.yaml default. Additionally, project and system scoped
entries in clouds.yaml will always have a consistently-named entry
created so that these can be referenced externally.
Change-Id: Ibd53d8c8231e2b989841b590f4596e842b5aab82