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

Change-Id: I2d2ebf5b305d6d06b8d01c49d4d67e7ff050f5d4
diff --git a/vendor/google.golang.org/grpc/backoff.go b/vendor/google.golang.org/grpc/backoff.go
index ff7c3ee..542594f 100644
--- a/vendor/google.golang.org/grpc/backoff.go
+++ b/vendor/google.golang.org/grpc/backoff.go
@@ -48,7 +48,10 @@
 // here for more details:
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
 //
-// This API is EXPERIMENTAL.
+// Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
 type ConnectParams struct {
 	// Backoff specifies the configuration options for connection backoff.
 	Backoff backoff.Config