Follow-up from "Add test case for `first_class_vulnerabilities` feature flag"

Contributes to #214654

The following discussion from !29278 (merged) should be addressed:

• @splattael started a discussion:

  Since we've haven't translations for these strings CI failed (https://gitlab.com/gitlab-org/gitlab/-/jobs/513784133).

  Let's fix this in a follow-up MR 👍

Things to do

• Run rake gettext:regenerate
• Commit changes on locale/gitlab.pot
• Update specs in ee/spec/features/groups/group_overview_spec.rb file to use translated strings instead of hard coded ones like so; expect(page).to have_content _('Detected')