Background push notifications showing messageIncoplete error

[skhamis]

This regression was introduced in #17222 due to us moving the Viaduct initialization out of RustFirefoxAccounts which NotificationService was relying on.

Steps to reproduce

1. Have firefox in the background
2. Send a notification from another device

Expected behavior

1. The push notification shows up with the sent tab (or signed in notification)

Actual behavior

Semi-related issue: #17313 (comment)
Related issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1864480

Device & build information

• Device: ?
• Build version: ?
• First seen version: ?

Notes

Attachments:

┆Issue is synchronized with this Jira Task

[cpeterso]

The first Firefox iOS build with this messageIncomplete error is build 9000 (35974). The previous build, 9000 (35936), correctly shows a notification with the sent URL.