enable env WALG_VERIFY_PAGE_CHECKSUMS

[cp319391]

I would like to enable this flag WALG_VERIFY_PAGE_CHECKSUMS in the postgresql CR. to verify the backups. ref https://wal-g.readthedocs.io/PostgreSQL/#page-checksums-verification

for example:

apiVersion: acid.zalan.do/v1
kind: postgresql
metadata:
  name: xyz
  namespace: xyz
 spec:
  env:
  - name: WALG_VERIFY_PAGE_CHECKSUMS          ### is not enabled or visible at path `/run/etc/wal-e.d/env`
    value: "true"
  - name: USE_WALG_BACKUP
    value: "true"
  - name: USE_WALG_RESTORE
    value: "true"
  - name: WALG_AZ_PREFIX
    valueFrom:
      secretKeyRef:
        key: WALG_AZ_PREFIX
        name: azure-client
    value: "7" 

Please make available env WALG_VERIFY_PAGE_CHECKSUMS in https://github.com/zalando/spilo/blob/master/postgres-appliance/scripts/configure_spilo.py#L824 that may enable us to configure it at my end.
Or let us know if it can be done in an another way.