fix(iOS): don't reference PrivacyInfo.xcprivacy twice for new projects (#46457)

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:

```ruby
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:

![CleanShot 2024-09-12 at 13 23 21@2x](https://github.com/user-attachments/assets/44e5bb55-a1ab-4b4b-bfe4-e4a6808afd15)

## Changelog:

[IOS] [FIXED] - don't reference PrivacyInfo.xcprivacy twice for new projects

Pull Request resolved: https://github.com/facebook/react-native/pull/46457

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

Reviewed By: cortinico

Differential Revision: D62580116

Pulled By: cipolleschi

fbshipit-source-id: 1224a41307ae6c9b862832f145baf0edc92476d6

packages/react-native/scripts/cocoapods/privacy_manifest_utils.rb

@@ -67,14 +67,29 @@ module PrivacyManifestUtils
     end
 
     def self.ensure_reference(file_path, user_project, target)
-        reference_exists = target.resources_build_phase.files_references.any? { |file_ref| file_ref&.path&.end_with? "PrivacyInfo.xcprivacy" }
-        unless reference_exists
-            # We try to find the main group, but if it doesn't exist, we default to adding the file to the project root – both work
-            file_root = user_project.root_object.main_group.children.find { |group|
-                group.class == Xcodeproj::Project::Object::PBXGroup && (group.name == target.name || group.path == target.name)
-            } || user_project
-            file_ref = file_root.new_file(file_path)
-            build_file = target.resources_build_phase.add_file_reference(file_ref, true)
+        privacy_info_filename = File.basename(file_path)
+
+        # Check if the file is already in the PBXBuildFile section
+        build_phase_reference_exists = target.resources_build_phase.files_references.any? { |file_ref| file_ref&.path&.end_with?(privacy_info_filename) }
+
+        unless build_phase_reference_exists
+            # Check if the file is already in the PBXFileReference section
+            existing_file_reference = user_project.files.find { |file| file.path&.end_with?(privacy_info_filename) }
+
+            if existing_file_reference
+                # If the file reference exists, add it to the build phase
+                target.resources_build_phase.add_file_reference(existing_file_reference, true)
+            else
+                # If the file reference doesn't exist, add it to the project and the build phase
+                # We try to find the main group, but if it doesn't exist, we default to adding the file to the project root - both work
+                file_root = user_project.root_object.main_group.children.find { |group|
+                    group.class == Xcodeproj::Project::Object::PBXGroup && (group.name == target.name || group.path == target.name)
+                } || user_project
+                puts "file_root: #{file_root}"
+
+                file_ref = file_root.new_file(file_path)
+                target.resources_build_phase.add_file_reference(file_ref, true)
+            end
         end
     end