Add Security Context Constraint (SCC) for Helm Deployment

[smooti]

Is your feature request related to a problem? Please describe.
When deploying the minio-operator on an OpenShift cluster in a newly created namespace (ex. minio-operator) an SCC error is commonly presented to the user. This has been reported as an issue #289 with no real resolution other than a user having to manually provision their own SecurityContextConstraint before provisioning the minio-operator.

Describe the solution you'd like
Reading over documentation from rook.io it looks like they have addressed this issue by adding in a conditional which creates the SecurityContextConstraint if it detects that it is running on an OpenShift cluster. The documentation going over OpenShift and SecurityContextConstraints can be found here. The helm chart template file that creates the SCC resource can be found here.

Describe alternatives you've considered
Creating an SCC resource separately before helm installation.

Additional context
Add any other context or screenshots about the feature request here.