For localization file locales how do I know what region code to use? For example when I put the translations.xml under fr_CA and change the Roku to French the strings are translated correctly, but if I put them under fr_FR and have the Roku in French it reverts back to English translations. Will fr_CA work for a Roku in France? What about South America? Will es_ES work for all of South America, or do I need to have a translations.xml for each country?