Curator job in Elasticsearch helm chart has a condition on
api version batch/v2alpha1. Cronjob resource is deprecated
in batch/v2alpha1 from k8s 1.8 and batch/v1beta1 is enabled
by default.
Remove the condition on API version as it is no more required.
Closes-Bug: #1753524
Change-Id: Ia296b3742e655fae508e5d4402e7f3881db31688