Update dir ownership for additionalVolumeMounts in initContainers

[BlueBlueSummer]

As of now, initContainers only update following mountpath during init step, but not for additionalVolumeMounts.

Background: I want to add an NFS for snapshot dir, and I add following configs,
`additionalVolumes:

• name: efs-mount
  nfs:
  path: /
  server: fs-xxxx.efs.eu-central-1.amazonaws.com

additionalVolumeMounts:

• name: efs-mount
  mountPath: "/qdrant/efs-snapshots"`

In this case, qdrant will fail to start due to permission issue.
Panic occurred in file lib/storage/src/content_manager/toc/mod.rs at line 126: Can't create a directory for snapshot of xxx: Permission denied (os error 13)

I tried to set additionalVolumeMounts to /qdrant/snapshots, but we already have a default item for this, so there will be 2 volumes mounting on same path, and cause failure