Issue:

Check Media shows incorrect values when media filenames contain special characters (spaces, %, &, =, etc.) on Android, while the desktop version works as expected.

Cause:

According to the [Anki manual](https://docs.ankiweb.net/media.html#media), filenames with spaces or special characters appear differently in the HTML editor compared to how they are stored on disk. For example, hello 100%.jpg is displayed as hello%20100%25.jpg in the editor.

HTML encoding is likely applied because certain characters have special meanings in URLs and HTML syntax. Without proper encoding, the card rendering engine may fail to locate or display media files with special characters in their names.

For instance, if a file named test,.jpg is referenced in a card, it gets encoded as test%2C.jpg in the editor for proper rendering, while the actual file on disk remains test,.jpg.

Observations:

• When adding a card using the desktop version, the original filename is stored in the collection.anki2 database (notes table).
• When adding media via Android, the filename is stored in an encoded format.
  Scrrenshot of the notes table :

This discrepancy causes the check_media function to return incorrect results for media files added from Android when their names include special characters.

Approach

Now, while adding card in a deck addNote() function is called
https://github.com/Sahil06012002/Anki-Android/blob/fb3eec394463e19f0b3db3fdaa5b6b1eb156879a/AnkiDroid/src/main/java/com/ichi2/anki/NoteEditor.kt#L1198
that stores the note in the database.

Decoding the media filenames before storing them in the database resolves the issue.
Before calling addNote(editorNote!!, deckId), the fields parameter in editorNote is updated to replace encoded filenames with their decoded versions :
https://github.com/Sahil06012002/Anki-Android/blob/fb3eec394463e19f0b3db3fdaa5b6b1eb156879a/AnkiDroid/src/main/java/com/ichi2/anki/NoteEditor.kt#L2579 .

Fixes

• Fixes Check Media Deletes Used Files #17972

How Has This Been Tested?

• Tested on a physical device (Android 12).
• Attached a video demonstrating the fix in
  https://github.com/user-attachments/assets/721fba7e-07d0-4523-a851-3f8bfc7f6910

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