Testing with languages not available on Android devices with cellular connection

I'm attempting to test using a language other than what is listed under Languages for a Samsung S5, an older Samsung device with an Ice Cream sandwich OS, and a Motorola device with JellyBean OS. My available languages under Language & Input do not include the ones I need. My Android tablets have all languages, so those are fine. It is just occurring on devices that have cellular service (Sprint & Verizon). I have installed language packs for my desired languages, have installed a GPS faker, and have set my keyboards to include the languages. All without luck.