(PUP-1737) Use symbols on display checking
(PUP-1737) Use symbols on display checking

This ensures that unnecessary items don't show up in ace.to_s in the way it was
before conversion to symbols.

DSI-Ville-Noumea/puppetlabs-acl,cyberious/puppetlabs-acl,DSI-Ville-Noumea/puppetlabs-acl,cyberious/puppetlabs-acl,MelanieGault/puppetlabs-acl,cowofevil/puppetlabs-acl,ferventcoder/puppetlabs-acl,MelanieGault/puppetlabs-acl,puppetlabs/puppetlabs-acl,ferventcoder/puppetlabs-acl,cowofevil/puppetlabs-acl