* Enable sub-languages on app first run.
* Fix wrong language code string parsing.
* Fix some build issues due to rebase.
* Use PreferenceHelper and remove an extra preference.
* Remove a constant.
(cherry picked from commit 084e6a964ee2f2a8499b861e5e3e58938ddab6e9)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/extension/ExtensionManager.kt
5ee6029395