Description of problem:

dpa.spec.configuration.velero.args.garbage-collection-frequency has wrong description. As per upstream docs garbage collection runs every hour by default. 
https://velero.io/docs/v1.13/how-velero-works/#set-a-backup-to-expire

https://github.com/vmware-tanzu/velero/blob/2f25c2590831f8eb11ef8ebd8db6963b59c6cd5d/pkg/controller/gc_controller.go#L41

Version-Release number of selected component (if applicable): 
OADP 1.3.1

How reproducible: 
Always

Steps to Reproduce:
1.

Actual results:

garbage-collection-frequency has a wrong default frequency   

$ oc explain dpa.spec.configuration.velero.args.garbage-collection-frequency
KIND:     DataProtectionApplication
VERSION:  oadp.openshift.io/v1alpha1
FIELD:    garbage-collection-frequency <integer>
DESCRIPTION:
     How long to wait by default before backups can be garbage collected.
     (default 720h0m0s)

Expected results:

gc-controller runs its reconciliation loop every hour by default.

Additional info: