If I run your SDK Examples, 3D object at geolocation, the earth object correctly appears.
If I copy the EXACT code and files into my Android project, the earth model does not render. The indicator works and points me to where the world should be, but there is nothing there.
It is not a path error as I have setup the folders in the exact same way ( indicator works ) and there are no error thrown in the JS console.
Nice that you were able to sort it out by yourself and you can continue with your testings now.
NVM, was a permission problem.