Updated stx-monitor to use official Elastic 7.6.0 helm-charts for Kibana,
Filebeat, Metricbeat and Logstash.
This change included updating the helm-elastic tarball sha to the newest
release and updating helm-elastic patches accordingly. Patched the
charts to support previous stx-monitor functionality and updated the
manifest to conform to the new config format.
Change-Id: I03b356b2b7acda0fc8336704784bd870252dd5b8