I don't know the features of your "android smart box".
Do you plan to simply connect your DNS-327L to it like an USB stick? So that it will be recognized as a mass storage device?
This won't work for (at least) 2 reasons:
1.) You can't physically connect them with a simple USB extension cable. You would need a cable with 2 male ends which is not standard.
2.) You can't logically connect them. In the USB world, you always need 1 server-style device at one end and (at least) 1 client-style USB-device (e.g. stick) at the other. Just as you also can't simply connect 2 self-contained systems (computers, NAS, tablet etc.) via USB. To circumvent this restrictions for connections of 2 PCs, there are special cables to do this (e.g.
here). But I think this won't work for your NAS (or not as you intend)