Description of problem:
Currently, golden images namespace is hardcoded in SSP.
If a user creates a dataImportCron via HCO, they cannot specify a custom namespace.
The dataImportCron will be created in the golden images namespace.


Version-Release number of selected component (if applicable):
CNV 4.10.0

How reproducible:
100%

Steps to Reproduce:
1. Add custom dataImportCron to HCO, set a namespace


Actual results:
SSP rejects the update

Expected results:
DataImportCron should be created in the custom namespace.

Additional info:
metadata:
  name: kubevirt-hyperconverged
spec:
  dataImportCronTemplates:
  - metadata:
      name: custom-data-import-cron
      namespace: golden-images-update-boot-source-test-ssp-data-import-crons
    spec:
      managedDataSource: dummy
      schedule: '* * * * *'
      template:
        spec:
          source:
            registry:
              url: registry.redhat.io/rhel8/rhel-guest-image
          storage:
            resources:
              requests:
                storage: 10Gi

Error:
E           HTTP response body: b'{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"admission webhook \\"validate-hco.kubevirt.io\\" denied the request: admission webhook \\"validation.ssp.kubevirt.io\\" denied the request: dataImportCronTemplates validation error: invalid namespace in DataImportCronTemplate custom-data-import-cron: must be empty or openshift-virtualization-os-images","reason":"dataImportCronTemplates validation error: invalid namespace in DataImportCronTemplate custom-data-import-cron: must be empty or openshift-virtualization-os-images","code":403}\n'