Add missing parameter descriptions to the PHPDocs for `WP_Upgrader_Skin::decrement_update_count()` and `Bulk_Upgrader_Skin::decrement_update_count()`.

See #27700.


git-svn-id: https://develop.svn.wordpress.org/trunk@27996 602fd350-edb4-49c9-b593-d223f7449a82
Align parameters in the hook docs for the `attachment_thumbnail_args` filter.

See #27700.


git-svn-id: https://develop.svn.wordpress.org/trunk@27997 602fd350-edb4-49c9-b593-d223f7449a82