Fire on-add-or-edit-cups-printer with correct params

- on-add-or-edit-cups-printer should be fired with a result_code and
a printer_name rather than a bool and printer_id.

Change-Id: Ie3486a62e4c1b6090ca9cce4b028b799f3de0112
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1649175
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#667730}