04-07-2014 03:34 AM - edited 04-07-2014 03:35 AM
How to repackage an Android app is described on the Runtime for Android site for developers.
04-07-2014 04:56 AM
Taking your question at face value there is none, it will need a substantial rewrite as Android is Java and Native is C++.
Native apps also usually use QML to define the layout and control some of the logic.
@oliver_kranz suggestion is the easiest way to get an existing Android app on to BB10 but obviously it will still look like an Android app lacking the Cascade UIX.