- Use variables with more descriptive names
- Add comment blocks about us being okay doing this for SaaS-only
  experiments
- Fix both instances of hard-coded plan IDs for experiments to point to
  the correct plans!
  - Previously, the TrialStatusWidgetHelper one was pointing at the
    production Gold (no longer a thing) plan ID
  - And the PaidFeatureCalloutHelper one was actually pointing at the
    sandbox (oops!) Premium plan ID