Add React Native workspace detection

[susanshi]

A typical react native project will have the following characteristics, in the order of how accurately it indicates that this is a react-native project.

1. React-native mentioned as a dependency in package.json
2. A react-native folder inside node_modules
3. An “android” and an “ios” folder at the top level
4. Usually an index.android.js and index.ios.js at top level

Due to performance and privacy restrictions, we understand only #3 and #4 can be implemented.
Please report workspace as ReactNative if 3 AND 4 is met.