Language support

[Rafael Fontenelle]

Hello,

It seems flatpak only recognizes languages with two characters, like
en, pt, sv". For me, setting 'pt' (European Portuguese) works, but
'pt_BR' (Brazilian Portuguese) fails. See:

$ LC_ALL=C flatpak config --set languages pt_BR
error: 'pt_BR' does not look like a language code

This impacts on the details of software listed. e.g. I'd expect GNOME
Boxes's name be, in pt_BR, "Boxes" but flatpak shows "Caixa" which is
pt's translation.

Any particular reason for not supporting variants of languages in
"cc_LL" format, link en_US, en_GB, pt_BR ?

Best regards,
Rafael Fontenelle