Update test name.

test/unit/legacy-noattributes.html

@@ -117,7 +117,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         assert.ok(def);
       });
 
-      test('native property observeable via `attributeChanged` and reflected to property when `_forceObservedAttributes` is used', () => {
+      test('native properties observeable when `_legacyForceObservedAttributes` set', () => {
         el = document.createElement('x-native-attrs-force');
         document.body.appendChild(el);
         el.tabIndex = 5;