Port C# to new API

src/csharp/ext/grpc_csharp_ext.c

@@ -673,7 +673,9 @@ grpcsharp_call_start_serverside(grpc_call *call, callback_funcptr callback) {
 GPR_EXPORT grpc_server *GPR_CALLTYPE
 grpcsharp_server_create(grpc_completion_queue *cq,
                         const grpc_channel_args *args) {
-  return grpc_server_create(cq, args);
+  grpc_server *server = grpc_server_create(args);
+  grpc_server_register_completion_queue(server, cq);
+  return server;
 }
 
 GPR_EXPORT gpr_int32 GPR_CALLTYPE
@@ -706,7 +708,7 @@ grpcsharp_server_request_call(grpc_server *server, grpc_completion_queue *cq,
 
   return grpc_server_request_call(
       server, &(ctx->server_rpc_new.call), &(ctx->server_rpc_new.call_details),
-      &(ctx->server_rpc_new.request_metadata), cq, ctx);
+      &(ctx->server_rpc_new.request_metadata), cq, cq, ctx);
 }
 
 /* Security */