Apply overrides.css to buffet apps
Apply overrides.css to buffet apps

Previously, overrides.css was being ignored, because the overrides.css
was empty for all the buffet-style apps.

https://phabricator.endlessm.com/T11172

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib