Uncomment fsgroup by default in provided values file

[gss-jmorris]

Description of Change

The default values file should include fsGroup: 2000 under the podSecurityContext map. Mounted volumes will not be writeable without this permission, which means users installing this chart for the first time will have containers stuck in a CrashLoopBackOff unless this value is a default setting.

resolves #220

Things to Do Before Submitting

• Have you signed the Sonatype CLA?
• Have you added and run automated tests for your change? (See the README)
• Have you run helm lint on your change?

[jflinchbaugh]

Thank you for contacting us. I've applied a similar fix with automated tests and updates to the documentation as part of another PR: https://github.com/sonatype/helm3-charts/pull/227