You might be able to write an ndk app targeting android with you own stack of widget, but that's very different from an 'sdk' app.
Now that you mention it mobile support seems to be in flux: http://stackoverflow.com/questions/20860931/is-it-possible-t...
http://gluonhq.com/products/mobile/javafxports/get/ <-- android, iOS, ARM
However it seems to be a barebones solution as it lacks mobile-specific controls (they want you to buy Gluon Mobile for that)