insights: Cannot create an insight from All Insights dashboard

Created by: CristinaBirkel

I see this on k8s.

Repro steps:

1. Navigate to the All Insights dashboard
2. Hit "Create New Insight"
3. Choose either Search or Langstats insight to create

Error: unmarshalDashboardID: unmarshalDashboardID: illegal base64 data at input byte 4

I believe this is caused by the dashboard id being set to virtual, which is not in the right id format and the BE won't accept it. I'm not sure what the solution is here.