grafana image: fix permissions for provisioned dashboards & datasources
FROM grafana/grafana:7.1.5
-COPY provisioning/dashboards/* /etc/grafana/provisioning/dashboards/
+COPY --chown=grafana:grafana provisioning/dashboards/* /etc/grafana/provisioning/dashboards/
-COPY provisioning/datasources/* /etc/grafana/provisioning/datasources/
+COPY --chown=grafana:grafana provisioning/datasources/* /etc/grafana/provisioning/datasources/
