Updating to latest protos and device-management interface, releasing 2.0

Change-Id: I2d2ebf5b305d6d06b8d01c49d4d67e7ff050f5d4
diff --git a/vendor/google.golang.org/grpc/preloader.go b/vendor/google.golang.org/grpc/preloader.go
index 76acbbc..0a1e975 100644
--- a/vendor/google.golang.org/grpc/preloader.go
+++ b/vendor/google.golang.org/grpc/preloader.go
@@ -25,7 +25,10 @@
 
 // PreparedMsg is responsible for creating a Marshalled and Compressed object.
 //
-// This API is EXPERIMENTAL.
+// Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
 type PreparedMsg struct {
 	// Struct for preparing msg before sending them
 	encodedData []byte