Site Health: Consistently pass an object to the `auto_update_{$type}` filter...

Site Health: Consistently pass an object to the `auto_update_{$type}` filter in Site Health debug data.

Previously, some instances of the filter received an array from a plugin or theme update response, potentially triggering PHP notices.

Merges [48745] to the 5.5 branch.
Reviewed by desrosj, SergeyBiryukov.
Props bpayton, pbiron.
Fixes #50852.
Built from https://develop.svn.wordpress.org/branches/5.5@48747


git-svn-id: https://core.svn.wordpress.org/branches/5.5@48509 1a063a9b-81f0-0310-95a4-ce76da25c4cd