remove dependency on github.com/census-instrumentation/opencensus-proto

[codyoss]

Open Census is now deprecated and the project mentioned archive has been archived for over a year. I have seen some dependency issues popping up in the go/proto/grpc space and have traced it back to this dependency having a really old refs on google.golang.org/genproto in this repo. Is there a plan to remove this dependency from the tree? As another issue pointed out, which I have linked below, this can also pose a security risk to depend upon projects that are not getting updated.

Previous issue that was autoclosed: #952