GRPCAction specifies an action involving a GRPC service.
Port number of the gRPC service. Number must be in the range 1 to 65535.
Service is the name of the service to place in the gRPC HealthCheckRequest (see https://github.com/grpc/grpc/blob/master/doc/health-checking.md). If this is not specified, the default behavior is defined by gRPC.