Removed update_appt_presentation flag.

[brianseek]

Summary

Removes check_in_experience_updated_appt_presentation flag. This was a frontend flag used only on vets-website and has been removed from the frontend code and pushed to production already.

Related issue(s)

• [FE] Remove Feature Flag checkInExperienceUpdatedApptPresentation va.gov-team#55515

Testing done

No testing. Feature flag only.

What areas of the site does it impact?

Feature toggles

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog or Grafana (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

[kanchanasuriya]

LGTM