React Native Config Cocoapods Scripts may not Run if NPM is used

[jlandrum]

After hours of troubleshooting and getting nowhere, and as a creature of habit using npm, I found that the scripts that generate the native defines can randomly and forever stop running, except on the very first build, even if you nuke all temporary files and build caches.

Upon clearing node_modules then using yarn instead, the scripts began running. It may be useful to include in the readme
that yarn should be used. I'm not sure why this makes a difference but it does - I was unable to find any reasoning behind it
as it's rather unusual, the same files seem to be downloaded/created but Cocoapods does not seem to like it when npm is used.