Summary:
`OTHER_CFLAGS` doesn't seem to work when the file is imported from Objc++. This causes flipper to not be included.
## Changelog
[iOS] [Fixed] - Use `GCC_PREPROCESSOR_DEFINITIONS` to set `FB_SONARKIT_ENABLED`
Pull Request resolved: https://github.com/facebook/react-native/pull/33972
Test Plan: Tested the change in an app. Used a breakpoint to see that flipper code is not executed before this change, and is after. Also made sure other `GCC_PREPROCESSOR_DEFINITIONS` set by cocoapods are still properly inherited.
Reviewed By: cipolleschi
Differential Revision: D37001624
Pulled By: dmitryrykun
fbshipit-source-id: 920f3fe368a9fbe2cde9aa1e6d5b3b883c42119d
Janic Duplessis
77e6bff629