Add SCC and doc for sidecar openshift permissions

[sjberman]

Sidecars require a specific SCC in order to function in OpenShift, so we've added that SCC to our helm chart and a note to our docs telling users how to attach to it.

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• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have checked that all unit tests pass after adding my changes
• [x] I have updated necessary documentation
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• [x] I will ensure my PR is targeting the main branch and pulling from my branch from my own fork