Enter key no longer works on "Open this site in your assigned Container?" page

[Exagone313]

• Multi-Account Containers Version: 8.0.2
• Operating System + Version: Arch Linux
• Firefox Version: 94.0
• Other installed Add-ons + Version + Enabled/Disabled-Status: not relevant

Actual behavior

When a website is configured to open in a particular container, but the decision has not been remembered, it shows the Open this site in your assigned Container? page.

When pressing the enter key, it doesn't validate the button Open in <selected container> Container

Actually the button is not focused:

Expected behavior

When pressing the enter key, it should open the website in the selected container.

The button is expected to be focused:

Steps to reproduce

1. Assign a website to container
2. Open a new tab and visit the website
3. On the Open this site in your assigned Container? page, press enter.

Notes

This is a regression from the version 8.0.1, which is in fact the 7.x version:

Version 8.0.1
Released Nov 2, 2021 - 178.47 KB
Works with firefox 67.0 and later
Restoring previous version for some users who may have been accidentally updated prematurely 8.0.

The autofocus attribute of the button attribute has been removed in commit 05dc48e:

-        <button id="deny" class="button">Open in <dfn id="current-container-name">Current</dfn> Container</button>
-        <button id="confirm" class="button primary" autofocus>Open in <dfn class="container-name"></dfn> Container</button>
+        <button id="deny" class="button" data-message-id="openInContainer" data-message-arg="current-container-name"></button>
+        <button id="confirm" class="button primary" data-message-id="openInContainer" data-message-arg="container-name"></button>

I'm working on a PR.

[nabeelr]

I'd like to add fuel tho this fire. This is really annoying and should be corrected.
The highlighted button is always expected to be the action when a person hits the enter key. That not happening breaks UI convention going back more than 40 years.