Add EMAIL environment variable to review app

When seeding the database, the seed needs to draw an email from either
the EMAIL environment variable, or from the user's git login - which
isn't available in review apps. We need to set an EMAIL env var when
setting up a review app so that it can populate the db accordingly.

Co-authored-by: Laurence de Bruxelles <laurence.debruxelles@dsit.gov.uk>

Author: SamJamCul

.review_apps/ecs_task_definition.tf

@@ -47,6 +47,7 @@ locals {
   forms_admin_env_vars = [
     { name = "DATABASE_URL", value = "postgres://postgres:postgres@127.0.0.1:5432" },
     { name = "GOVUK_APP_DOMAIN", value = "publishing.service.gov.uk" },
+    { name = "EMAIL", value = "review-app-submissions@review.forms.service.gov.uk" },
     { name = "PORT", value = "3000" },
     { name = "RAILS_DEVELOPMENT_HOSTS", value = local.admin_app_hostname },
     { name = "RAILS_ENV", value = "production" },