Logstash: Add option to configure PVC labels in StatefulSets

[martinlillemets]

Allows adding custom labels to PVCs created by StatefulSets

• Chart version not bumped (the versions are all bumped and released at the same time)
• Updated template tests in ${CHART}/tests/*.py

close #1655

[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?

[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?

[cla-checker-service]

💚 CLA has been signed

[martinlillemets]

I dont know how to link an existing issue to this ticket but i created a issue before i created this PR:
#1655

[botelastic]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. To track this PR (even if closed), please open a corresponding issue if one does not already exist.

[martinlillemets]

/bump still waiting for review

[botelastic]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. To track this PR (even if closed), please open a corresponding issue if one does not already exist.