firebase/testing can't connect to firestore emulator after 0.16.1 version.  #2417

[REQUIRED] Describe your environment

• Operating System version: MACOS 10.15.1
• Browser version: not affecting
• Firebase SDK version: 7.5.2
• Firebase Product: testing

[REQUIRED] Describe the problem

connection to emulator firestore instance timeouts after upgrading testing library from 0.16.0 to 0.16.1 or 0.16.2.

Steps to reproduce:

Below code timeouts after upgrading from "@firebase/testing": "0.16.0" to "@firebase/testing": "0.16.1"

Start firestore emulator firebase emulators:start --only firestore

Relevant Code:

import * as firebase from '@firebase/testing';

const app = firebase.initializeAdminApp({ projectId: 'testing' });
const db = app.firestore();
db.collection('test')
  .doc('doc1')
  .set({ ok: true })
  .then(ref => console.log('set succeeded'))
  .catch(err => console.error('set errored', err));