refactor(animations): single animation engine code pass

packages/upgrade/src/common/downgrade_component_adapter.ts

@@ -92,7 +92,7 @@ export class DowngradeComponentAdapter {
         // for `ngOnChanges()`. This is necessary if we are already in a `$digest`, which means that
         // `ngOnChanges()` (which is called by a watcher) will run before the `$observe()` callback.
         let unwatch: any = this.componentScope.$watch(() => {
-          unwatch();
+          unwatch('');
           unwatch = null;
           observeFn((attrs as any)[input.attr]);
         });