Fix test suite when running on a feature branch

Summary:
Test suite for React Native version check relies on `ReactNativeVersion.js` file that is modified on a release branch (it contains values of a real version, not zeros).

That makes it impossible for the build to pass: https://circleci.com/gh/facebook/react-native/23494

This PR mocks it with zero values, just like we mock it in other suites. I am not sure if that is desired, but works for now.

CC ide
Closes https://github.com/facebook/react-native/pull/16464

Differential Revision: D6100285

Pulled By: hramos

fbshipit-source-id: 784f7e14f5283403f3fa518940565e1ef19dd398