Remove the old wp_auto_updates_maybe_update cron event. Schedule the new wp_maybe_auto_update event at 7 a.m. and 7 p.m. in the site's timezone.

see #27704.


git-svn-id: https://develop.svn.wordpress.org/trunk@25825 602fd350-edb4-49c9-b593-d223f7449a82