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'