Expose image list in node status

Change image manager to use repotag

pkg/kubelet/container/runtime.go

@@ -319,7 +319,7 @@ type Image struct {
 	// ID of the image.
 	ID string
 	// Other names by which this image is known.
-	Tags []string
+	RepoTags []string
 	// The size of the image in bytes.
 	Size int64
 }