Missing AVIF image support

Description

WordPress is able to generate AVIF images from media uploads for a long while via the official WordPress Performance Team's plugins. With WordPress 6.8, AVIF image support is now a core feature. Yet, AVIF images are not handled well by the WordPress Android App: esp. in the post editor, AVIF images cannot be picked from the media library selector (all AVIF images show as placeholders, not their proper thumbnails) and in the editor itself, the AVIF images are shown as placeholders, too.

There are more issues with AVIF support during media upload + the following serverside image format transformation, such as the WordPress Android app considering the upload as having failed because the server is busy transforming the e.g. JPEG original to AVIF so that the app doesn't receive the expected response, sometimes causing the app to attempt re-upload, which in turn creates more unnecessary derived images on the server's media library. But that it something that would almost be bearable compared to the above-mentioned issue inside the post editor.

Step-by-step reproduction instructions

1. Enable AVIF image transformations on WordPress
2. Use WordPress Android app to upload a JPEG
3. Observe the upload being perceived as failed, but ignore that and delete the unnecessary derived images
4. Go to the post editor inside the WordPRess Android app and attempt to pick the transformed AVIF image for your post
5. The AVIF image will only show as placeholder in the media picker AND in the editor

Screenshots, screen recording, code snippet

No response

Environment info

WordPress 6.8, most recent WordPRess for Android Native App.

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