Accurately captures severity level at time of incident report (#4655)

Co-authored-by: Jeffery Bennett <[email protected]>
Co-authored-by: Will Sheldon <[email protected]>

src/dispatch/incident/service.py

@@ -166,9 +166,10 @@ def create(*, db_session, incident_in: IncidentCreate) -> Incident:
         incident_priority_in=incident_in.incident_priority,
     )
 
-    incident_severity = incident_severity_service.get_default(
+    incident_severity = incident_severity_service.get_by_name_or_default(
         db_session=db_session,
         project_id=project.id,
+        incident_severity_in=incident_in.incident_severity,
     )
 
     cost_model = None