fix: Add privacyInfo reference for new projects to prevent PrivacyInfo being added twice

[okwasniewski]

Summary:

This PR fixes an issue with PrivacyInfo files.

When generating a new project for using the latest RC 0.76.0.rc0 I got two privacy manifests references in Xcode.

This is because PrivacyManifestUtils look for build phase reference:

reference_exists = target.resources_build_phase.files_references.any? { |file_ref| file_ref&.path&.end_with? "xcprivacy" }

Which doesn't exist for the generated template.

Here is how Xcode file tree looks like after installing pods:

We can also fix this inside of PrivacyManifestUtils utility but Im not sure which one is better.

When you create this file in Xcode its added to the PBXBuildFile section so the utility works good for existing projects, this issue only appears in newly generated projects.

Changelog:

[IOS] [FIXED] - Don't add PrivacyInfo to Xcode references twice

Test Plan:

1. Generate a new project
2. Execute pod install
3. Check if only one PrivacyInfo file exists

[okwasniewski]

Let me know if you prefer this to be handled in PrivacyManifestUtils inside of Core

[okwasniewski]

cc: @cipolleschi

[cipolleschi]

Yeah, it would be better to fix it in Core. Otherwise this change will popup to every project that wants to migrate, while if we do it in core, the first time that users do pod install we will be able to fix the project for them.

[okwasniewski]

Linking to the PR for visibility: https://github.com/facebook/react-native/pull/46457