[VOL-4292] OpenOLT Adapter changes for gRPC migration

Change-Id: I5af2125f2c2f53ffc78c474a94314bba408f8bae
diff --git a/vendor/google.golang.org/protobuf/CONTRIBUTORS b/vendor/google.golang.org/protobuf/CONTRIBUTORS
new file mode 100644
index 0000000..1fbd3e9
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at https://tip.golang.org/CONTRIBUTORS.