Grafana source configuration prometheus scrape interval default value

Hi…
I use a grafana “datasource.yml” defining prometheus specs.
I did not understand the reason why in the datasource configuration in grafana it does not keep the parameters of scrape_interval and timeout.
I got the app in a docker stack and every time I restart it I have to insert the due fugure.
Are ok the names into “datasource.yml” like below?
If I delete this file… all setting will come into sqllite db?
This is a little bit confusing to me… 'cause it’s important setting… I scrape every 60s and default in Grafana is 15s and many graph are empty in some circumstance… so I need 60s default always write down.
Please let me know where is the trick.
Thanks Alen , Italy.

apiVersion: 1
datasources:
- name: Prometheus
  type: prometheus
  url: http://prometheus:9090
  isDefault: true
  access: proxy
  editable: true
  scrape_interval: 60
  scrape_timeout: 30