Alerting: Fix unmarshalling of GettableStatus to include time intervals (#112602)
* move test files into test-data
* add test for the bug
* populate time-intervals of gettableStatus config
(cherry picked from commit 5f9a51418c)
Co-authored-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>
grafana-delivery-bot[bot]