Update test content for coronavirus_landing_page_steps
Update test content for coronavirus_landing_page_steps

Test was previously using the `coronavirus_landing_page.json` file, now that we have hardcoded the content we need to update these test accordingly.

Co-authored-by: Rosa Fox <7730dfe70100dfd32d4a03b4b554258d5d0f44a0@digital.cabinet-office.gov.uk>

alphagov/collections,alphagov/collections,alphagov/collections,alphagov/collections