Privacy: Cleanup `.wp-policy-help` CSS remnants and add back-compat when...

Privacy: Cleanup `.wp-policy-help` CSS remnants and add back-compat when hiding the tutorial content before copying.

Props garrett-eclipse.
Fixes #49282.
Built from https://develop.svn.wordpress.org/trunk@47112


git-svn-id: https://core.svn.wordpress.org/trunk@46912 1a063a9b-81f0-0310-95a4-ce76da25c4cd