getLanguage() only returns the language code which can be
ambiguous in case of UI localization, when there are more
than one language variants. Fallback to the first variant
caused mixed language UI, e.g. en-US vs. en-GB, pt vs. pt-BR,
zh-CN vs. zh-TW.
Change-Id: I888423cd4b3c65dbdb900ff3b6bc308fa119be4d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/96285
Tested-by: Jenkins
Reviewed-by: Andras Timar <andras.timar@collabora.com>