[TS] Compatibility with grpc-js

[Manh Nguyen Tien]

I reported the issue in grpc-js repo but it seems like there's something we should do with FB's code generator.
Affected version: 2.0.

Details: grpc/grpc-node#2070

Environment

• OS name, version and architecture: Ubuntu 20.04 amd64
• Node version: v12.13.0
• Node installation method: nvm
• Package name and version: grpc-js - 1.5.10

[Manh Nguyen Tien]

Possible fixes merged but haven't been released. I think I can use that version. Someone contributed several days after 2.0.0 release last year. #6654