Icon URL is missing from tabs sync data

[lougeniaC64]

Steps to reproduce

1. Open Firefox iOS
2. Sign in
3. Open a few tabs
4. Click Sync Now from the settings menu
5. Navigate to about:sync in desktop

• This will require installing the About Sync add-on

6. Scroll to the bottom of the page and expand the tabs items

• You may need to trigger a sync in desktop before the tabs created in step 3 appear

Expected behavior

Tabs records for iOS clients should have populated icon values.

Actual behavior

Tabs records have null icon values.

Notes

This is a longstanding issue that may be related to issues with the population of other tabs properties like lastUsed and title. I am seeing that nil values are passed into the icon property in Tab.toRemoteTab, but when I change icon: nil to icon: tab.currentFaviconUrl ?? nil I'm still not seeing the icon value come through.

┆Issue is synchronized with this Jira Task