use min_over_time for vsphere prometheus alerts
This is a follow up to https://github.com/openshift/cluster-storage-operator/pull/126#discussion_r558055393
The PR is included in 4.7.0-0.nightly-2021-01-21-235301, and the alter lgtm, so I'll mark this as verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: OpenShift Container Platform 4.7.0 security, bug fix, and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2020:5633