Merge pull request kubernetes#36267 from vishh/gci-mounter-scope

Automatic merge from submit-queue

Make GCI nodes mount non tmpfs, ext* & bind mounts using an external mounter 

This PR downloads the stage1 & gci-mounter ACIs as part of cluster bring up instead of downloading them dynamically from gcr.io, which was the cause for kubernetes#36206.

I have also optimized the containerized mounter to pre-load the mounter image once to avoid fetch latency while using it.

Original PR which got reverted: kubernetes#35821

```release-note
GCI nodes use an external mounter script to mount NFS & GlusterFS storage volumes
```

@mtaufen Node e2e is not re-enabled in this PR.

cc @jingxu97

pkg/cloudprovider/providers/openstack/metadata.go

@@ -95,7 +95,7 @@ func getMetadataFromConfigDrive() (*Metadata, error) {
 
 	glog.V(4).Infof("Attempting to mount configdrive %s on %s", dev, mntdir)
 
-	mounter := mount.New()
+	mounter := mount.New("" /* default mount path */)
 	err = mounter.Mount(dev, mntdir, "iso9660", []string{"ro"})
 	if err != nil {
 		err = mounter.Mount(dev, mntdir, "vfat", []string{"ro"})