Incorporate the ES fixes to the Kibana build
See [ES MR](https://dccscr.dsop.io/dsop/elastic/elasticsearch/elasticsearch/merge_requesMR].
Changes include :
- Maintain the ability to build the UBI image within Elastic's environment, while still running fine in DCAR:
- override the
NEXUS_SCHEME
to usehttp
, but have it default to https - override the
NEXUS_SERVER
to use our own server, but have it default to dcar's server
-
Adopt the build-scripts/prepare.sh. The script was made generic enough to download any artifact at any url. In Kibana's case, we need both the kibana tarball and a dumb-init script.
-
Re-enable the GPG check and remove code not used in DCAR's context