I know the response came a bit late, but you can take a look here: http://wiki.ros.org/Robots/Tangobot. This hasn't been yet announced here (it's a work in progress), but the code is publicly available already.
And the answer is yes :) it is possible indeed. It uses RosJava, RosAndroid, and the cross compiled version of the navigation stack. Feel free to take a look there!