When trying to re-install ceph chart, the
ceph-namespace-client-key-generator job is not working because of the
already created pvc-ceph-client-key secret.
So it needs to remove the secret when deleting ceph chart.
Closes-Bug: #1705177
Change-Id: I7338a516fe3b9f265953b8b1fddd3dbfb97bafd2
892f9bd839