feat: do not clear feature flags on remote config error

[ioannisj]

💡 Motivation and Context

Closes #367

Do not clear local flags on remote config error or when hasFeatureFlags is not false

💚 How did you test it?

Added a couple of unit tests

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.