Add gRPC 1.24.2 with Go 1.13, protobuf 3.10.0, and protoc-gen-go 1.3.2

[swoldemi]

Added environment variables to make subsequent updates a bit easier as well.

[linux-foundation-easycla[bot]]

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• :x: Simon Woldemichael (51fc25fe8144943c3a809c25d4d9855b80350769)