Consider relative to pwd installation root when looking for files in …

…rn module via cocoapods

The :reactNativePath provided by use_native_modules! is the rn module path relative to the installation root (usually ./ios). However, when executing cocoapods from a dir thats not the installation root, packages that use the relative :reactNativePath variable in their path must also consider the relative to pwd installation root.

This fixes usage of cocoapods with the --project-directory flag like

bundle exec pod install --project-directory=ios

scripts/react_native_pods.rb

@@ -277,8 +277,9 @@ def modify_flags_for_new_architecture(installer, cpp_flags)
 end
 
 def build_codegen!(react_native_path)
-  codegen_repo_path = "#{react_native_path}/packages/react-native-codegen";
-  codegen_npm_path = "#{react_native_path}/../react-native-codegen";
+  relative_installation_root = Pod::Config.instance.installation_root.relative_path_from(Pathname.pwd)
+  codegen_repo_path = "#{relative_installation_root}/#{react_native_path}/packages/react-native-codegen";
+  codegen_npm_path = "#{relative_installation_root}/#{react_native_path}/../react-native-codegen";
   codegen_cli_path = ""
   if Dir.exist?(codegen_repo_path)
     codegen_cli_path = codegen_repo_path
@@ -319,7 +320,7 @@ def checkAndGenerateEmptyThirdPartyProvider!(react_native_path)
     Pod::Executable.execute_command(
       'node',
       [
-        "#{react_native_path}/scripts/generate-provider-cli.js",
+        "#{relative_installation_root}/#{react_native_path}/scripts/generate-provider-cli.js",
         "--platform", 'ios',
         "--schemaListPath", temp_schema_list_path,
         "--outputDir", "#{output_dir}"