[ticket/11857] Use passed service collection instead of container in manager

The service collection that was already passed to the avatar manager should
be used in the avatar manager method get_driver() instead of the container
itself.

PHPBB3-11857
Merge remote-tracking branch 'marc1706/ticket/11857' into develop

* marc1706/ticket/11857:
  [ticket/11857] Use passed service collection instead of container in manager