GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS not evaluated when building for Objective-C

[Martin Winter]

Hello,

I am building Protobuf as an Objective-C framework via Cocoapods. In the macOS app that is using the framework, we have the Clang flag `CLANG_WARN_QUOTED_INCLUDE_IN_FRAMEWORK_HEADER` set to 1 and would like to keep it that way. It seems that Protobuf has the flag `GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS` for this specific purpose, and it is set to 1 by default in the configuration files. This seemed to have been included in the .m files previously, as can be seen in this GitHub issue:

https://github.com/protocolbuffers/protobuf/issues/3060

However, I can no longer see these #if statements in the code. It would be great if this could be fixed soon. I am also happy to create a new bug report if that would be helpful

Thanks

Martin