Google does not seem interested in making the NDK anything more than implementing Java native methods, 3D graphics, audio or porting code from other platforms.

Everything else should be done at Java level.

I understand from the point of view of security, but what is safer, provide bindings to libraries already validated and installed on the device or forcing devs to package something else?

Also even though they implement native APIs in nice C++ with RAII and stuff, it gets exposed as unsafe C APIs, so the security story isn't 100% correct.