fix: load video tags via relative src instead of file:// URI

[Ayush-Patel-56]

Purpose / Description

Fixes an issue where video files in [sound:] tags fail to load due to CORS policies blocking file:/// paths when the WebView base URL is http://127.0.0.1.

Fixes

Fixes #20668

Approach

Replaced the file:/// URI generation for <video src="..."> with just the raw relative filename.

The ViewerResourceHandler will natively intercept these requests and respond with Range headers over HTTP. This cleanly solves the cross-origin bug without sacrificing video seeking capabilities or needing an external activity.

How Has This Been Tested?

Built locally. Tested on a flashcard with an embedded video file to verify that the inline <video> tag loads the player and successfully plays back with functioning playback/scrubbing controls.

Video:

untitled.mp4

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[BrayanDSO]

Please test it with some special chars that probably should be encoded: %, , numbers, kanji, emoji, etc

[Ayush-Patel-56]

Thanks for pointing it out, I've updated the PR with URI encoding for the src attribute and fixed the path resolution in ViewerResourceHandler. Using the filename test % 123 汉字 😄.mp4, the video loads and plays perfectly!

[BrayanDSO]

Asked for a apkg for reproduction in the original issue #20668 (comment)

[Ayush-Patel-56]

sent apkg file in the comment #20668 (comment)