The tor-android repo contains a TorResourceInstaller. This is an !Android/Java library that Orbot uses. We need this.
The tor-android repo also contains the native Tor libraries. We don't want to use these. So the Tor-Android project will need to depend on our own versions of these native libraries.
We have the last two on our radar for desktop platforms, see #22341 (moved). But there has not been done any work to tackle that bug. As I said in that ticket starting with zstd sounds good. I am fine supporting lzma right from the beginning, too. (What about zlib support which we currently have on desktop?)
I highly recommend getting rid of all the asset unpacking code from Orbot. It is ancient and long unneeded, and indeed problematic. The libtor.so created by https://github.com/guardianproject/tor-android/pull/21 can be directly included in the TBB APKs by putting them in the right place on the file system before building. In tor-android, this is done in tor-android-binary/src/main/libs with tor-android-binary/src/main/jniLibs a symlink to that.
Then Android will automatically handle all the unpacking in a much more secure way. And it can be either loaded as a shared library without setting any paths, e.g. System.load("tor") or directly executed as a daemon from /data/data/org.torproject.torbrowser/lib/libtor.so.
If you still need to unpack other assets like torrc, geoip, etc., those should be put into the projects assets/ folder, then there is a standard Android method for getting those asset files. I think Orbot was already doing that.