This unbreaks Translate and CleanChanges who depend on the constant. Change-Id: I8bfb9e2aaeb77351beefb130f71daeee4e07afae
Retaining the UniversalLanguageSelector.php and Resources.php to avoid breaking support for old MW versions. At some point, we can validate how many old MW versions we need to support. Bug: T87987 Change-Id: I006e968b70298b54013177aa792a4dfdf5b6aae2