Update grpc and io_opencensus_cpp

[ghost]

See grpc/grpc#18080

Pinging @devjgm

The problem as mentioned in the above issue is that abseil moved the location of a file. As a result, the version of io_opencensus_cpp we are using breaks. We need to update it too.

This PR doesn't update protobuf per #2090 yet, because I'm not entirely sure if we need to.

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Codecov Report

Merging #2131 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2131   +/-   ##
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  Coverage   92.87%   92.87%           
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  Files         300      300           
  Lines       17696    17696           
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  Hits        16435    16435           
  Misses       1261     1261

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[coryan]

I am sad about using SHAs for the dependencies. Can we wait until gRPC and protobuf release a compatible version? Or can we just update the protobuf version and override the gRPC preference?

[devjgm]

I am sad about using SHAs for the dependencies. Can we wait until gRPC and protobuf release a compatible version? Or can we just update the protobuf version and override the gRPC preference?

There should be a new release of grpc that works as soon as grpc/grpc#18080 is resolved. And open census had the v0.3.0 release on Jan 31 (https://github.com/census-instrumentation/opencensus-cpp/releases). Would that released version work for us so we don't need to depend on a commit hash?

[ghost]

There is a PR to backport the fix to 1.19.x: grpc/grpc#18202

And the opencensus release should work because it refers to the new file location.

[coryan]

I think we should wait until gRPC makes a new release with the fix you mentioned above. Thanks for you patience with this.

Reviewable status: 0 of 2 files reviewed, all discussions resolved (waiting on @coryan and @devjgm)