Context: I'm using OpenCV for a Unity project. I already made a simple .dll plugin to wrap the C++ code I use to fit my needs on Editor / PC. Now I need a .so or .jar plugin to do the same for Android compatibility. For the life of me, I cannot wrap my head around all the JNI / NDK stuff. I cannot use OpenCV Java or OpenCV4Android, as these two have some bugs / missing features that I'm actually using: in particular, they're missing BOWs and the ability to load SVMs.
All current tutorials I have googled either fall back to OpenCV4Android or assume familiarity with the JNI / NDK, familiarity which I have zero of.
Question: In as detailed and step by step a manner as possible, how do I include and use C++ OpenCV in Android Studio.