Follow-up from "Enable sync with package metadata db by default"

The following discussions from !130176 (merged) should be addressed:

• @ahmed.hemdan started a discussion:

  suggestion (non-blocking): I understand it's unlikely for the PURL_TYPES hash to move around package_metadata.rb file, but I think it would be better to use the permalink here.

• @ahmed.hemdan started a discussion:

  suggestion (non-blocking): Perhaps we could assign [12] to something identifiable so that it's not a magic number? Or better yet, use Enums::PackageMetadata::PURL_TYPES[:cbl_mariner] here? REMOVED, SEE COMMENT BELOW!