Use the my files app and go to internal storage > android > data > echoproject.adastra.game > files and make a copy of the saves folder in it to your downloads folder or something. Once a copy of the saves folder has been made, delete the previous version of the game and install the new one. Open the new game and make a save or something so it establishes that a save has been made, then go back to the game's files folder and overwrite the new saves folder with the old one