So implementing android localization is easy. First make sure everything (text) needs to be translated is in the xml file. Then we use the following tool to convert the xml file into xliff translation files.

Convert XLIFF language translation files

After the conversion, we can send xliff to any people to translate. The fastest and most convenient way to translate interfaces — Poedit This can be a very nice xliff editor. Anyone (without any programming knowledge will be able to edit that file using Poedit)

After translation, using the above conversion tool to convert xliff file back to .xml file.

This is what I found when working for Kinetic Commerce for Lowes client. Their app needs to be translated into French and I will have to found a way to easy translation. For iOS, you can export and import xliff file directly. However, on Android, other than directly send .xml file, there is not an easy way found.

I tried using csv file, but copy from translation tools no longer works anymore in newer version of Android Studio.