Disk space of all containers is not monitored

Created by: slimsag

We only have one-off monitoring for some containers, and not in all deployment environments. We should monitor disk space of all containers that use persistent volumes

Once finished, custom metrics for monitoring this like those in precise-code-intel-bundle-manager and gitserver (see https://github.com/sourcegraph/sourcegraph/pull/10496/files#diff-3ddde7d2f9759f91b4b4b13bdadddf62R58 ) should be removed from Grafana.