ceph: minor update init container script in generateVaultGetKEK
ceph: minor update init container script in generateVaultGetKEK

Replacing VAULT_KV_VERS with VAULT_BACKEND for specifing version of kv engine.

Signed-off-by: Jiffin Tony Thottan <ac134a614b50f2e879db85acb9f4b45b24a210dc@gmail.com>

rook/nfs,rook/nfs,rook/rook,rook/nfs,rook/rook,rook/rook,rook/rook,rook/rook