Automatic merge from submit-queue (batch tested with PRs 36626, 37294, 37463, 37943, 36541)

Use tmpfs for gluster-server container volumes.

Gluster server needs a filesystem that supports extended attributes for its data. Some distros (Debian, Ubuntu) ship Docker that runs containers on aufs, which does not support extended attributes and therefore Gluster server fails there.

We can use tmpfs for Gluster server data volumes. ~~This expects that host's /tmp is tmpfs, which is true for  Debian, Ubuntu, RHEL, CentOS and Fedora.~~

I reworked it to mount tmpfs inside the container, the server pod is privileged.

And *after* this PR is merged and new Gluster server container image is pushed we need to bump the image version in https://github.com/kubernetes/kubernetes/blob/master/test/e2e/volumes.go#L407

Edit: I also fixed Gluster server Dockerfile, it was not working at all.