Fake ObjectReaction should handle PartialObjectMetadata special

When a client requests a PartialObjectMetadata returned from the
ObjectReaction type, if the object has a GVK set use that instead
of what the schema returns, since the majority of clients getting
partial object metadata will be doing so using the metadata client
or server side conversion.

staging/src/k8s.io/client-go/testing/fixture.go

@@ -318,6 +318,11 @@ func (t *tracker) Add(obj runtime.Object) error {
 	if err != nil {
 		return err
 	}
+
+	if partial, ok := obj.(*metav1.PartialObjectMetadata); ok && len(partial.TypeMeta.APIVersion) > 0 {
+		gvks = []schema.GroupVersionKind{partial.TypeMeta.GroupVersionKind()}
+	}
+
 	if len(gvks) == 0 {
 		return fmt.Errorf("no registered kinds for %v", obj)
 	}