12.3 bump

Youtube playback fixes (#3917)

* Always force a YT desktop redirect to get 360 videos.

* Fix videos playback/projection issues

Disable building Oculus 3dof in TC (#3894)

Update AMO to the FxR one (#3872)

Add a warning message when password is left empty. (#3867)

Fix Login select glitch (#3857)

Do not show login save/select if autofill is disabled (#3848)

Import l10n. (#3819)

Show tray buttons tooltip at the bottom (#3770)

* Show tray buttons tooltip at the bottom

* Fix tray notifications margin

Remove vimeo UA override