I don't know how exactly it's done, but a person I know was making a translated build for Android easily.
1. You had to open .apk as an archive and replace strings.properties and encounters.json files.
(Previously you could also replace the UI elements, but they're encrypted currently to take up less space).
2. Then you needed an Android Studio, and to download a library for actual Android version (some forums of Android developers should have them). Using Studio you could make the .apk structure correct, so any Android device would run it.
I think older Android versions (like 9, lol) could run the .apk without the second step, but newest wouldn't unfortunately.