Add Minio Client Image to Chart.yaml and Values.yaml in Loki template

When enabling minio in Loki the helm release gives a nil pointer error, specifically Helm upgrade failed for release logging/logging-loki with chart loki@6.6.4-bb.1: template: loki/templates/admin-api/deployment-admin-api.yaml:52:28: executing "loki/templates/admin-api/deployment-admin-api.yaml" at <.Values.minio.mcImage.repository>: nil pointer evaluating interface {}.repository.

It appears that minio in the loki values.yaml doesn't refer to any image/repository that the template/admin-api/deployment-admin-api.yaml references.

A fix is required so that minio can be deployed by Loki.