Wrong variant cache tags are added and never invalidated

Problem/Motivation

Currently, ComponentVariantsHooks::overrideComponentId rewrites the #component key to enforce rendering of a variant if such is present or to instruct the twig loader to render the base component if the __default keyword is present in #variant.

However, the fix that introduced this change didn't account for the rewrite of the #component key and missed corresponding changes in ComponentVariantsHooks::addVariantCacheability and this causes adding of cache tags that are never invalidated.

Steps to reproduce

• Render a variant in a controller via render element
• Change the template of the variant and save
• Check the output on the controller