One would suppose that, given a host with different numbers of applicable and installable packages, a search for 'has installable_rpms' and 'has applicable_rpms' would have different results. However, the two searches have the same results.

https://github.com/Katello/katello/blob/8dc78dd030b51729faf5eb81b30278dee2d9ced7/app/models/katello/host/content_facet.rb#L379-L382

The issue might be that `joins_installable_rpms` searches Katello::ContentFacetApplicableRpm.

see discussion: https://community.theforeman.org/t/hosts-match-has-upgradable-rpms-but-have-no-upgradable-rpms/44387/7?u=jeremylenz