Make prometheus pod wait task resilient to redeployment

The Ansible task that waits for the `prometheus-metric-storage-0`
pod to become `Ready` was failing intermittently.

In order to make retries/delay work, we need a until condition
in order to make it working.

Signed-off-by: Chandan Kumar (raukadah) <raukadah@gmail.com>

Author: raukadah

ci/playbooks/prometheus_admin_api.yaml

@@ -18,3 +18,5 @@
           oc wait pod prometheus-metric-storage-0 --for=condition=Ready -n openstack --timeout=1m
       retries: 10
       delay: 30
+      register: oc_wait_result
+      until: oc_wait_result.rc == 0