Restore original properties of the right now (activity) and primary (news) dashboard widgets.

This avoids issues with those trying to remove/disable core meta boxes.

fixes #26392.

Built from https://develop.svn.wordpress.org/trunk@26611


git-svn-id: http://core.svn.wordpress.org/trunk@26501 1a063a9b-81f0-0310-95a4-ce76da25c4cd