Fix bug 1265: fix error in k8scluster-list with helm and juju opState

K8scluster-list was showing errors when getting helm-chart and
juju-bundle operational state when keys were no present.

Change-Id: Iaf1e9d7cc7137ec6ea33bb458a4759f150c8d5d2
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>