Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49666
This change moves the index.js file to the `releases` folder, giving it a meaningful name.
It also rename the prebuild folder to ios-prebuild to be more descriptive.
It finally removes the old scripts that this refactoring supersedes.
bypass-github-export-checks
## Changelog:
[INTERNAL] - Move the infdex.js to the prepare-ios-prebuilds script.
Reviewed By: cortinico
Differential Revision: D70176043
fbshipit-source-id: e0c3f3bd53adf97fa388c37a746d274fd678f690