[Bug]: ephemeralIntentFlags appears to do nothing on android

[andyregen]

Description

I have tried setting intent flags to ephemeralIntentFlags for android but when i logout and log back in again it always remembers my user and instantly logs me in.

using preferEphemeral on ios works as intended.

I have also tried upgrading to version 5.0.0-alpha.3 in the hopes that the new android auth implementation would fix this but sadly i am still experiencing it

Minimal Reproduction

Here is my implementation:

```dart
  final result = await FlutterWebAuth2.authenticate(
    url: url,
    callbackUrlScheme: 'regen',
    options: const FlutterWebAuth2Options(
      preferEphemeral: true,
      intentFlags: ephemeralIntentFlags,
    ),
  );
```

1. Login on an android device, for the purposes of this test i am specifically using microsoft authentication but i dont think this makes a difference?

2. Logout again

3. Login again, user is remembered and instantly logged in.

Exception or Error

When logging in for a second time my credentials are remembered and i am automatically logged in

Expected Behaviour

When logging in for a second time i should be made to reenter login credentials and not be remembered

Screenshots

No response

Additional context

No response

Device

Android Emulator, Android Device

OS

Android 14

Browser

Samsung Internet, Chrome

Flutter version

3.32.1

flutter_web_auth_2 version

4.1.0, 5.0.0-alpha.3

Checklist

• I have read and followed the entire troubleshooting guide and it has not provided the solution I need.
• I have provided all the information I can.