gRPC migration

Change-Id: Ib390f6dde0d5a8d6db12ccd7da41135570ad1354
diff --git a/vendor/google.golang.org/grpc/go.mod b/vendor/google.golang.org/grpc/go.mod
index ecef1ab..dc56aa7 100644
--- a/vendor/google.golang.org/grpc/go.mod
+++ b/vendor/google.golang.org/grpc/go.mod
@@ -3,11 +3,11 @@
 go 1.11
 
 require (
-	github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f
-	github.com/envoyproxy/go-control-plane v0.9.4
+	github.com/envoyproxy/go-control-plane v0.9.0
+	github.com/envoyproxy/protoc-gen-validate v0.1.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/mock v1.1.1
-	github.com/golang/protobuf v1.3.3
+	github.com/golang/protobuf v1.3.2
 	github.com/google/go-cmp v0.2.0
 	golang.org/x/net v0.0.0-20190311183353-d8887717615a
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be