Comment 3 for bug 1850916

We already deal with permissions by recommending end-users use `setfacl` to give them access to the Mistral directory for accessing the Ansible content: https://docs.openstack.org/project-deploy-guide/tripleo-docs/latest/deployment/ansible_config_download.html#ansible-project-directory

We should move the cache to be under /var/lib/mistral/ to align with having all of the Ansible content there.