879edcbc32
Alerting: Fix simplified routing group by override (#86552)
* Alerting: Fix simplified routing custom group by override
Custom group by overrides for simplified routing were missing required fields
GroupBy and GroupByAll normally set during upstream Route validation.
This fix ensures those missing fields are applied to the generated routes.
* Inline GroupBy and GroupByAll initialization instead of normalize after
(cherry picked from commit 71445002b7)