I haven't looked into this that much, so I don't know how much insight this'll be but I did some cursory exploration into this not too long ago(I gave up cause my idea at the time was dumb ) and I imagine it's possible to build something like the iosNativeControls example.
A Cinder Android app lies inside of a NativeActivity(technically CinderNativeActivity but that's subclassing NativeActivity) which a subclass of an Activity, I think the IOS equivalent to an Activity might be an AppDelegate. Last I recall it's possible to nest Activities within one another so you could conceivably nest a Cinder instance within the activity of a larger main Android app, though that's not something I've tried. I know it's definitely possible to overlay Activities on top of each other, so that may be another path to explore.
The painful part, which is what I was focusing on learning about during my exploration, is communication between the main Android app and the Cinder instance. There are some wrappers for certain things built into the NDK, but in all likelyhood, you will probably have to write some custom wrappers between the Java and C++ to fully integrate with what you're building. It's not hard, but it's a lot of code.
The NDK has some examples, this one if I remember correctly was the one I was using as a guide to figure out C++ / Java communication.
Engine::ShowUI() - it should be calling the "showUI" function in the Java file here
There was someone on here that ported their app to Android from IOS, I can't remember the username at the moment though