helm chart - fix orchestrator service account/role creation

Currently this service account/role is created in ps-operator chart, but service account for orchestrator can be selected/changed from ps-db chart which doesn't make sense since we generate service account with ps-operator in the name and then in ps-db chart we cannot now what was the name selected in the other chart.

So either by default it needs to be fixed name (like it is temporarily done now) so that we know what it is or it needs to be generated name from ps-db chart.