I have successfully used REST API (from Rust) to call Google Maps to convert Lattitude/Longitude coordinates to the actual street address/location using this Maps API:
There is currently no gRPC interface for the Google Maps Geocoding API that allows you to convert latitude/longitude coordinates to a street address/location.
Based on this document, the Google Maps Geocoding API can only function through the REST interface.
I hope this information is helpful.
If you need further assistance, you can always file a ticket on our support team.