Summary:
Checking if Hermes is enabled is failing because there is no `podfile.lock` file in the directory where this script is executed and `USE_HERMES` will be set to `false` which will prevent building Hermes binary jsbundle.
## Changelog
[iOS] [Fixed] - `HERMES_ENABLED` check fixed in react-native-xcode.sh
Pull Request resolved: https://github.com/facebook/react-native/pull/34675
Test Plan:
1. Enable Hermes
2. Make a release build
3. Verify the `main.jsbundle` file is Hermes binary bundle
Reviewed By: cortinico
Differential Revision: D39686608
Pulled By: cipolleschi
fbshipit-source-id: 237c77ced484d4ab77e576c7a2bb7b6826228017