[Kibana] remove useless maxUnavailable in Kibana chart

[victorsalaun]

This PR removes useless maxUnavailable attribute in Kibana chart
Solves #331

• Chart version not bumped (the versions are all bumped and released at the same time)
• README.md updated with any new values or changes
• Updated template tests in ${CHART}/tests/*.py
• Updated integration tests in ${CHART}/examples/*/test/goss.yaml

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[jmlrt]

⛴

[jmlrt]

jenkins test this please

[jmlrt]

Thanks for this PR @victorsalaun,

One minor confusion between Pod Disruption Budget and Rolling Update Deployment which both contains a maxUnavailable parameter.

While the maxUnavailable parameter value was related to Pod Disruption Budget, which we don't implement in Kibana chart, we can still specify updateStrategy.rollingUpdate.maxUnavailable value when changing Deployment update strategy from recreate to rollingUpdate, so test_override_the_default_update_strategy should continue to test this scenario.

[jmlrt]

Actually, this test should stay like that as it's testing adding a Rolling Update strategy to Kibana Deployment which is still valid, while maxUnavailable value should be used to define a Pod Disruption Budget resource as in Elasticsearch chart.

[victorsalaun]

Nice catch, indeed same name maxUnavailable but for different usage.
I reverted the deletion of the test.

[jmlrt]

⛴

[jmlrt]

jenkins test this please

[victorsalaun]

Thanks @jmlrt