no image preview for webp, when "image/webp" is specified

**Describe the bug**
If the image is uploaded with mimeType "image/webp" there is no preview in the ui.
If I upload the same data, but with "image/png" the preview is shown

**To Reproduce**
Steps to reproduce the behavior:

1. Upload a webp with the firebase sdk.
2. specify either "image/png" or "image/webp" as mime type
3. Go to the upload folder
4. Click the file, to see no/ the preview

**Expected behavior**
Webp preview shown when correct mimetype is specified

**Screenshots**

**Desktop:**

- OS: Linux Debian
- Browser: chromium
- Version: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36

Start by locating the upload-folder file preview handling and the MIME-type checks used when a file is opened. Reproduce the issue with the Firebase SDK using a WebP file marked as image/webp, then verify that the preview appears while the existing PNG behavior remains unchanged.

Written by the indexing model from the issue text.