Portkey App：fix the issue where the sound continues playing after the WebView is closed

[wade-portkey]

Description

When closing the WebView, the audio or video content continues to play in the background. This issue causes an unexpected and disruptive experience for users who believe that closing the WebView will stop all media playback.

Steps To Reproduce

1. Log in to the application.
2. Navigate to a section where a WebView is used to display content.
3. Play any audio or video content within the WebView.
4. Close the WebView by tapping the close button or performing the relevant action to exit the WebView.
5. Observe that the sound continues to play even though the WebView has been closed.

Current Behavior

• After the WebView is closed, the sound from the audio or video continues to play in the background.
• When the WebView is closed, the user expects all media playback to stop, but it does not, leading to a confusing user experience.
• This causes a bug where the application does not properly manage media resources after the WebView is closed.

Expected Behavior

• After closing the WebView, all audio and video playback should immediately stop.
• When the WebView is exited, the user should no longer hear any sound, ensuring that media does not play unintentionally in the background.
• This ensures that users have control over media playback and that the application behaves predictably.

Environment

• Platform: Portkey App
• Version: all version