[auth] [Google sign-in] Can not switch Google account after first sign in.

### Describe your environment

* Operating System version: OSX 10.11.6
* Browser version: Brave 1.1.23 / Firefox 71 / Safari 11.1.2
* Firebase SDK version: 7.5.0
* Firebase Product: auth (auth, database, storage, etc)

### Describe the problem

Before anything: this problem seems to happen in all browsers __except Google Chrome__ (v 79.0.3945.88).

- The first time a user signs in with Google, he gets an account list to select which one to use.
- After sign out, if the user tries to sign in again, the account he chose the first time is automatically used. __He can not choose another account__. The only way I've found is to clear all cookies / local storage.
- I am expecting the list to appear after sign out. Curiously of all the browsers I have tested (Safari, Brave, Firefox, Chrome), __Chrome__ does not _seem_ have this problem.

#### Steps to reproduce:

Same as above.

#### Relevant Code:
I use `signInWithPopup` method:

```
const provider = new firebase.GoogleAuthProvider()
await firebase.auth().signInWithPopup(provider)
```