Double file extensions get mutated improperly

[AngelTomkins]

Steps to reproduce

1. Enter a room that has a file saved with a double file extension such as .tar.xz
2. Press and hold on the screen until the popup menu comes up.
3. Press save
4. Check the name of the file downloaded

Outcome

What did you expect?

The downloaded file's filename should have the intact .tar.xz

What happened instead?

The downloaded file's filename will look something like this: my_file.tar_202405141906.xz

Your phone model

Google Pixel 8

Operating system version

Android 14

Application version and app store

1.6.14 [40106142] (F-310cecf5) F-Droid

Homeserver

kde.org

Will you send logs?

No

Are you willing to provide a PR?

No