Fixed symbol mapping to slices (#54641)

Summary:
Previously the symbolication support when using the precompiled React.XCFramework copied the symbol bundles to the wrong folder in the framework, causing Xcode to not find the symbols.

This commit fixes this by copying symbols to the correct slice folders instead of in the root of the framework folder.

Note:
Running `pod cache clean --all` and `rm -rf Pods` in the iOS folder followed by a clean rebuild in Xcode might be a good thing to ensure you're using the correct binaries when compiling.

## Changelog:

[IOS] [FIXED] - Fixed copying symbol bundles into correct slice folder

Pull Request resolved: #54641

Test Plan:
```
npx react-native-community/cli init Next --version next --skip-install
cd Next
yarn
cd ios
bundle install
RCT_USE_RN_DEP=1 RCT_USE_PREBUILT_RNCORE=1 RCT_SYMBOLICATE_PREBUILT_FRAMEWORKS=1 bundle exec pod install
```

Run Xcode and observe that you are not able to step into React Native source code.

After this fix, you should be able to step into the source code of React Native.

Reviewed By: cortinico

Differential Revision: D87919202

Pulled By: cipolleschi

fbshipit-source-id: 029bca3e182c170562e358beb50592d5b91d8e8b

Author: chrfalch

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

@@ -233,7 +233,16 @@ def self.process_dsyms(frameworkTarball, dSymsTarball)
 
             # Add the dSYMs folder to the framework folder
             rncore_log("  Adding dSYMs to framework tarball")
-            `(cd "$(dirname "#{dsyms_tmp_dir}")" && mkdir -p React.xcframework && cp -r "$(basename "#{dsyms_tmp_dir}")" React.xcframework/dSYMs && tar -rf "#{frameworkTarPath}" React.xcframework/dSYMs && rm -rf React.xcframework)`
+
+            # Move symbol bundles into each of the slices in the xcframework
+            # Example:
+            # move dSYMs/ios-arm64/. into React.xcframework/ios-arm64/React.framework/dSYMs/.
+            Dir.glob(File.join(dsyms_tmp_dir, "*")).each do |dsym_path|
+                slice_name = File.basename(dsym_path)
+                slice_dsym_dest = File.join("React.xcframework", slice_name, "React.framework", "dSYMs")
+                rncore_log("    Adding dSYM slice #{slice_name} into tarball at #{slice_dsym_dest}")
+                `(cd "#{File.dirname(frameworkTarPath)}" && mkdir -p "#{slice_dsym_dest}" && cp -R "#{dsym_path}/." "#{slice_dsym_dest}" && tar -rf "#{frameworkTarPath}" "#{slice_dsym_dest}")`
+            end
 
             # Now gzip the framework tarball again - remember to use the .tar file and not the .gz file
             rncore_log("  Packing #{Pathname.new(frameworkTarPath).relative_path_from(Pathname.pwd).to_s}")
@@ -246,6 +255,10 @@ def self.process_dsyms(frameworkTarball, dSymsTarball)
             # Remove backup of original tarballs
             FileUtils.rm_f("#{frameworkTarball}.orig")
 
+            # Remove temp dSYMs folder and the temp Framework folder
+            FileUtils.rm_rf(dsyms_tmp_dir)
+            FileUtils.rm_rf(File.join(artifacts_dir, "React.xcframework"))
+
         rescue => e
             rncore_log("Failed to process dSYMs: #{e.message}", :error)
             # Restore the original tarballs