After quite a bit of searching it seems there is no easy way to install data that have been included in apk.
It is recommended to use assets in apk and then the installed program would use java functions getAssets().open("path/file.ext") or getResources() to access the data stream in apk
I can't find getAssets() or getResources() in Harbour or QT.
I would rather not have to download separate Data, PRG, and other files during installation.