[bug]The user did not click "Start Broadcast"，but the isScreenShareEnabled() method returns true on iOS

[kongpf8848]

Describe the bug
The local user has not completed the screen sharing process and others can not receive the shared video stream，but isScreenShareEnabled() method return true

To Reproduce

1. run example app and click the screen share button to execute the following code:

     var track = await LocalVideoTrack.createScreenShareTrack(
        const ScreenShareCaptureOptions(
          useiOSBroadcastExtension: true,
          maxFrameRate: 15.0,
        ),
      );
      await participant.publishVideoTrack(track);

2. click outside the "Screen Broadcast" dialog，check return value of isScreenShareEnabled() method

Expected behavior
isScreenShareEnabled() return false

Platform information

• Flutter version: 3.27.1
  [✓] Flutter (Channel stable, 3.27.1, on macOS 15.2 24C101 darwin-arm64, locale
  zh-Hans-CN)
  • Flutter version 3.27.1 on channel stable at
  /Users/xxx/Desktop/jack/software/flutter
  • Upstream repository https://github.com/flutter/flutter.git
  • Framework revision 17025dd882 , 2024-12-17 03:23:09 +0900
  • Engine revision cb4b5fff73
  • Dart version 3.6.0
  • DevTools version 2.40.2

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
• Android SDK at /Users/kongpf/Library/Android/sdk
• Platform android-34, build-tools 34.0.0
• ANDROID_HOME = /Users/xxx/Library/Android/sdk
• Java binary at: /Applications/Android
Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 21.0.3+-79915917-b509.11)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 16C5032a
• CocoaPods version 1.15.2

• Plugin version: 2.3.3
• Flutter target OS: iOS
• Flutter target OS version: 15.5