Through some research I found a few relative things to note;
The minimum android-X version for art support is 21 -> https://developer.android.com/guide/practices/verifying-apps-art.html
That highest available stable build-tools for sdk release of sdk 21 is 21.1.2, the highest being 21.1.3(unstable)
I have a 5.1.1 device that I have cherry picked the above gerrit task in to rockbox and lowered the build requirements to android-21. And built against the latest ndk with sdk 21.1.2 then loading it on my 5.1.1 device. RaaA loads momentarily with a loading bar (the first time it runs) and then crashes.
I have also found BOOTDIR "/.rockbox" defined in android.h, but changing that to ./.rockbox or .rockbox did not help either
I have also simply tried to load a dummy app without jni calls and it still crashed, but in this case the executable was still packaged with in the apk.
Question, I understand the "purest" form of rockbox is straight up compile c and execute, but is running an all new main thread in pure java such a bad idea? One with its own way to show the ui menu, handle input and make calls to c functions, without the need for things like jni calls to compiled c in order to read a button press for the menu. Or is this the "great pain in the ass to make it work" that everyone has been talking about?
Edit: upon verifying my build-chain with a lower android api 4.2 I might have missed a few details, so I'm going to test 5.0 again
Edit2: Yes it actually does run on my 5.1.1 device