add severity override to instance level

ee/app/controllers/security/vulnerabilities_controller.rb

@@ -13,6 +13,7 @@ class VulnerabilitiesController < ::Security::ApplicationController
       push_frontend_feature_flag(:vulnerability_report_vr_badge, current_user, type: :beta)
       push_frontend_feature_flag(:vulnerability_report_vr_filter, current_user, type: :beta)
       push_frontend_feature_flag(:enhanced_vulnerability_bulk_actions, current_user, type: :wip)
+      push_frontend_feature_flag(:vulnerability_severity_override, current_user, type: :wip)
       push_frontend_feature_flag(:existing_jira_issue_attachment_from_vulnerability_bulk_action,
         current_user,
         type: :wip