Enable lvmetad and udev within the GD2 container

[kshlm]

This should help with lvm actions inside the container.

[JohnStrunk]

This needs a good bit of justification.
It greatly increases the dependencies on the host environment. In order to run a gd2 pod on a given host, one must ensure lvmetad and udev are running. I don't think we can move forward with this level of dependency... We can't assume that we have a way, or privileges, to make host changes.

[kshlm]

Most modern linux hosts should have udev and lvmetad enabled by default on the host (EL7 does). This could be a problem if GCS wanted to be deployed on a cloud providers managed K8S cluster, but if someone were already using a managed K8S I don't think they'd want to manage an infrastructure part like GCS on their own.

I'm marking this as do-not-merge, but leaving it open. I mainly opened this PR because we wanted to check if using lvmetad helps with the lv operations inside the GD2 pods. We're going to re-run scale tests with this and the updated container image to see if it helps. We'll get back to the justification for this change, if it really help.

[phoenix-bjoern]

We exactly had this problem and the patch helped us to deploy GCS. We would appreciate it this PR would be merged.