Adhere to Kubernetes Pod Security Standards

[onelapahead]

https://kubernetes.io/docs/concepts/security/pod-security-standards

We'll want to start working towards adhering to at least the baseline standard and eventually restricted. While most of that will fall onto the https://github.com/kaleido-io/firefly-helm-charts manifests, we do need to do our due diligence within the container images themselves such as setting USER, etc.

This issue is meant to track making updates to the FireFly core container image and any others to work towards the initial goal of meeting the baseline standard.