fix: bbolt data directory permissions

[algchoo]

Description of Changes

This PR updates the ownership and permissions for the bbolt data directory. It's configured to only add the necessary script (via a configMap) and initContainer if the backend is of type bbolt.

Based on the ticket, it's a little unclear to me whether or not these changes need to be applied to other deployments. The slack messages refer only to the bindplane container, I believe, so I started with that. It's also a bit unclear if we actually want to update the containerSecurityContext defaults.

Screenshot of the permissions when running locally on minikube with bbolt as backend:

Please check that the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• CI passes
• Changes to ports, services, or other networking have been tested with istio

[jsirianni]

@algchoo please increment the Chartfile minor version and run helm-docs command to update the readme. https://github.com/norwoodj/helm-docs