Incorrect instructions in Backup/restore guide version 2.7

Backup and restore guide omits backup and restore of openshift objects, namely secrets (and maybe configMaps?)

I did restore to new 3scale deployment (this should be standard way after the disaster; this is supposed process of template-to-operator migration) and it suffered from several issues.

zync didn't work unless I copied zync secret from old deployment

apicast didn't work unless I copied system-master-apicast from old deployment

still something else is needed to be copied/restored (system-seed? something else?) because during attempt to create new API/Product 3scale failed with 'Internal Error'