Update grpc to 1.22 to address some intermittent ent test failures (attempt2)

[ncabatoff]

I believe grpc/grpc-go#2818 is the cause of some of our intermittent test failures. The symptoms don't match exactly but they're close, and with this patch applied (along with my other fix) I wasn't able to provoke the "no handler for route" integ test failures. Note that this is apparently a fix for a 1.20 regression.

Process followed:

cd sdk
go get google.golang.org/[email protected]
go mod tidy
git commit
git push

cd ..
go get github.com/hashicorp/vault/sdk@update-grpc-attempt2
go mod tidy
git commit
git push

[jefferai]

This has the same problem. You're basing the repo SDK update on a commit on this branch but when the branch gets squashed and deleted that commit will no longer be valid.

You need to either do this in two separate PRs, or you need to just not PR it and just do it. :-)

[ncabatoff]

Now I follow! Ok, I'll just do it on master.