making user-secret in user-env optional to support IRSA (#353)

Issue #, if available:
N/A

Description of changes:
To start supporting IRSA in OpenShift clusters, the `user-secret` now needs to be optional.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Signed-off-by: Adam D. Cornett <adc@redhat.com>

Author: acornett21

templates/config/controller/user-env.yaml.tpl

@@ -14,4 +14,4 @@ spec:
               optional: false
           - secretRef:
               name: ack-{{.ServicePackageName}}-user-secrets
-              optional: false
+              optional: true