[VOL-4289]  Proto changes for gRPC migration

Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/google.golang.org/grpc/AUTHORS b/vendor/google.golang.org/grpc/AUTHORS
new file mode 100644
index 0000000..e491a9e
--- /dev/null
+++ b/vendor/google.golang.org/grpc/AUTHORS
@@ -0,0 +1 @@
+Google Inc.