Properly setup headers for FBReactNativeSpec in prebuilds (#52783)

Summary:
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Pull Request resolved: https://github.com/facebook/react-native/pull/52783

This change reverts D78158734 which was a patch to make the dynamic frameworks work properly because we were not exporting the FBReactNativeSpec headers in prebuilds correctly.

This change fixes this, by exposritng those headers correctly.

[Internal] -

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Reviewed By: cortinico

Differential Revision: D78803425

fbshipit-source-id: 5613ed0c790455ea86668eeb436f7b78a0c80918