[chart/redis-ha]Openshift Security Context

[Baboulinet-33]

What this PR does / why we need it:

Adapt pod security context for Openshift like bitnami do, remove the following properties:

• runAsUser
• runAsGroup
• fsGroup

Which issue this PR fixes

• fixes #285

Special notes for your reviewer:

I've generated multiple file with helm template test . before.template.txt: from master branch k8s-vanilla.template.txt: compability disable for like in k8s openshift.template.txt: compatibility enforced for openshift

openshift.template.txt k8s-vanilla.template.txt before.template.txt

[DandyDeveloper]

@Baboulinet-33 Things look good, just need version bumps on the chart. Need linting to pass before I merge.