Android app use stats from runner (#2801)

Summary:
Instead of calculating from the app, we use number reported by runner so it's the same as binary.

Right now we only report generated t/s from binary.

TODO: Create a Java class for other stats so that Java layer can get it through JNI.

Pull Request resolved: https://github.com/pytorch/executorch/pull/2801

Reviewed By: shoumikhin

Differential Revision: D55776409

Pulled By: kirklandsign

fbshipit-source-id: 116a939b703408a4b67d3b694213617a42ff2b81