build: move zone.js to angular repo (#30962)

PR Close #30962

packages/zone.js/test/rxjs/rxjs.util.ts

@@ -0,0 +1,12 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+export function supportFeature(Observable: any, method: string) {
+  const func = function() { return !!Observable.prototype[method]; };
+  (func as any).message = `Observable.${method} not support`;
+}