Use the new android_cmake build type to reduce recipe redundancy.
aarch64 is retained until a simple way to provide an abi list to
the new build type is found.
Rename the jni to cores-android as this is the main android
recipe and should track the latest ndk. Cores that cannot compile
with newer ndks should be moved to cores-android-rXX as needed.
This checks for the STRIPPATH varible in the android path. Only
setting that variable for the android cmake targets. JNI outputs
already stripped shared objects.