iOS App Stuck loading when locking/unlocking device after the Google Sign In dialog is shown

This was reported by a student of my course.

Reproduction steps

1. run the App on iOs simulator or real iOS device.

2. click on sign in with google button.

3. alert will popup "YOUR_APP_NAME Wants to Use 'google.com' to Sign In (Continue, Cancel)".

4. NOW lock the iOS device by pressing the device side button.

5. now unlock the iOS device.

you will notice that the spinner still working, and nothing you can do.

you must hot restart the app on simulator, or kill the app in real device.

you can use AppLifecycleState.resumed to reset variable.

but if you clicked on the button again you will get this error:

flutter: PlatformException(concurrent-requests, Concurrent requests to account signin, null)

flutter: message: PlatformException(concurrent-requests, Concurrent requests to account signin, null)

Reproduce the Google sign-in flow on an iOS simulator or device, then inspect the sign-in button handling and AppLifecycleState.resumed behavior. Done means unlocking no longer leaves the spinner stuck, and retrying sign-in does not produce the concurrent-requests error.

Written by the indexing model from the issue text.