Align openstack API downtime calculation

1. Divide OpenStack API check from metrics
2. Add recording rule to count api down of 5 consecutive minutes

Related-Prod: PROD-31017

Change-Id: Id21a3d8e367afbc24e3a71f788fa33d60bdb39d4
(cherry picked from commit d363e1e4b6d1b9492bac976649bce265b6d2d89e)
3 files changed