[v11.3.x] doc: Fix spacing in sample values for enabling persistence (#97238)

Co-authored-by: Irene Rodriguez <irene.rodriguez@grafana.com>
Co-authored-by: horacimacias <horacimacias@gmail.com>
Fix spacing in sample values for enabling persistence (#97220)

docs/sources/setup-grafana/installation/helm/index.md

@@ -222,9 +222,9 @@ To enable the persistent storage in the Grafana Helm charts, complete the follow
    ............
    ......
    persistence:
-   type: pvc
-   enabled: true
-   # storageClassName: default
+     type: pvc
+     enabled: true
+     # storageClassName: default
    .......
    ............
    ......