iPhone to Android is possible.
WhatsApp is not an Apple product. Contact the app developer here --> App Support or WhatsApp FAQ or Restoring your chat history - WhatsApp FAQ
WhatsApp Chat history from Google Drive to iCloud. (Android to iPhone)
Have you tried --> Move from Android to iPhone, iPad, or iPod touch - Apple ... and selected WhatsApp and its history? I don't think the Move process extracts data from Google Drive or any drive for that matter including iCloud Drive.
My experience says you can't transfer because on Android, WhatsApp, chat history is not stored on iCloud, on iOS it is.
That may be possible with third-party software. Warning!; WhatsApp data through third-party software has the risk of data being compromised. Because the data will be churned through third-party servers, which may or may not be encrypted. Be judicious while selecting the software and taking this call.