Add staging directory for kms

- Moves kms proto apis to the staging repo
- Updates generate and verify kms proto scripts to check staging repo

Signed-off-by: Anish Ramasekar <anish.ramasekar@gmail.com>

test/integration/controlplane/transformation/kms_transformation_test.go

@@ -37,9 +37,9 @@ import (
 	"k8s.io/apiserver/pkg/storage/value"
 	aestransformer "k8s.io/apiserver/pkg/storage/value/encrypt/aes"
 	mock "k8s.io/apiserver/pkg/storage/value/encrypt/envelope/testing/v1beta1"
-	kmsapi "k8s.io/apiserver/pkg/storage/value/encrypt/envelope/v1beta1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
+	kmsapi "k8s.io/kms/apis/v1beta1"
 )
 
 const (