Increase visibility of PhabricatorController::buildApplicationMenu methods
Summary: Ref T6822. This method needs to be public because it is called from PhabricatorApplicationSearchController::buildApplicationMenu().
Test Plan: I wouldn't expect increasing method visibility to break anything.
Reviewers: Blessed Reviewers, epriestley
Reviewed By: Blessed Reviewers, epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T6822
Differential Revision: https://secure.phabricator.com/D11416