Snippets: Some snippet region tags do not contain a product name

[bshaffer]

See googleapis/google-cloud-php#6864 (comment)

The Snippet Bot is complaining about the region tags (e.g. css_v1_generated_) because they are not "prefixed with a product name"

This may just be because the product prefix hasn't been added to gs://devrel-prod-settings/products.json (see googleapis/repo-automation-bots#4994), but the product css also might not be the right prefix (and instead it should be shoppingcss, for instance).

Do we have a way to customize these product prefixes for the snippets if we do indeed need to change them?