Web Share API Level 2 missing "Save Image" button on iOS 16

• Component: New Bugs
• Status: NEW ---

The "Save Image" button is now missing in iOS 16.2+. This makes it impossible to save images using the API.
Note that this may affect earlier versions of iOS 16 as well, but I don't have a device available to test.

Steps to reproduce:
1. Open https://w3c.github.io/web-share/demos/share-files.html
2. Deselect all checkboxes
3. Choose a file to share
4. Click "Share" to open the share sheet.
5. Observe that the "Save Image" button is missing from the share sheet.

Expected behavior: The "Save Image" button should be visible in the share sheet.
Actual behavior: The "Save Image" button is missing in the share sheet.

Impact: Users are unable to save images using the API, which can be a major inconvenience.

NOTE: When you display a preview of the image, the user can long press on the image, select share, and then the share sheet contains a "Save Image" button. But when calling the navigator via code, the "Save Image" button is missing. This can be observed here: https://8thwall.8thwall.app/capturephoto-aframe/. Take a photo, then compare the share sheets from the share button and from the long press.

[Radar WebKit Bug Importer]

<rdar://problem/108161919>