@easwars thanks for the revert.
It looks like the go interop build is still broken though, so perhaps more needs to be reverted.
https://source.cloud.google.com/results/invocations/47a57608-f03b-4882-80ef-c35fd801af5a/targets/github%2Fgrpc%2Finterop_docker_build/tests

$ GO111MODULE=on go get -d -v google.golang.org/grpc/...

<Seems fine>

GO111MODULE=on go get -d -v -t google.golang.org/grpc/...
go get: -t flag is a no-op when using modules
../../credentials/credentials.go:31:2: cannot find package "github.com/golang/protobuf/proto" in any of:
	/usr/local/go/src/github.com/golang/protobuf/proto (from $GOROOT)
	/go/src/github.com/golang/protobuf/proto (from $GOPATH)
...
...
...

I can't explain this. The first go get doesn't say it's downloading this package. But there are some packages it says it downloaded that the second go get fails to find.

Why is it looking in ...go/src though? With modules, it uses $GOPATH/pkg. I think even with this the go installs in the interop script are going to need GO111MODULE=on: grpc/grpc#24831, at which point the deps targets shouldn't actually be necessary. So maybe this PR wasn't needed after all.

Also see b/174073491 for some extra details (build_docker_go is still broken on master).