Include Samples for Grpc Proxy

## Include Samples for Experimental Grpc Proxy

The sample contains examples of invoking grpc and uses InvokeGrpcAsync

Will it be possible to include sample based on Grpc Proxy as shown here.

https://docs.dapr.io/developing-applications/building-blocks/service-invocation/howto-invoke-services-grpc/

Start by locating the existing sample that invokes gRPC with InvokeGrpcAsync and compare it with the linked Dapr gRPC proxy guide. Add a corresponding proxy-based sample alongside the existing example, then verify that it demonstrates the documented invocation flow and builds successfully.

Written by the indexing model from the issue text.