[18.03 backport] Replace deprecated grpc functions

[thaJeztah]

backport of #2645 for 18.03

git checkout -b 18.03_backport_replace_deprecated_grpc upsteam/bump_v18.03
git cherry-pick -s -S -x 2dfbafc1d21847497cc39c17b21363fb5c7332ab
git cherry-pick -s -S -x cb6dcf20536d8ebbd18c8f5c5c11e9c5074c212a
git push -u origin

[thaJeztah]

ping @anshulpundir @dperny - this change itself is not "critical", but it helps to get a clean cherry-pick with backporting some changes

[thaJeztah]

booooh. probably needs updates to grpc itself 🤔

/usr/local/go_workspace/src: warning: directory does not exist.
protoc --decode google.protobuf.FileDescriptorSet /usr/local/include/google/protobuf/descriptor.proto
/usr/local/include/google/protobuf/descriptor.proto: File does not reside within any path specified using --proto_path (or -I).  You must specify a --proto_path which encompasses this file.  Note that the proto_path must be an exact prefix of the .proto file names -- protoc is too dumb to figure out when two paths (e.g. absolute and relative) are equivalent (it's harder than you think).
2018/11/21 23:03:39 exit status 1
make: *** [protos] Error 1
Exited with code 2

[thaJeztah]

closing this as 18.03 is EOL