Add fluentd libvirt-exporter label

Also remove parsing sf-notifier logs file as
Docker is responsible for sf-notifier logs.

Change-Id: Id809b534239f818ca3660340d76345f4c10c7ac8
Related-bug: PROD-26897 (PROD:26897)
Related-bug: PROD-27026 (PROD:27026)
diff --git a/metadata/service/exporters/libvirt.yml b/metadata/service/exporters/libvirt.yml
index 2c910bb..e76a788 100644
--- a/metadata/service/exporters/libvirt.yml
+++ b/metadata/service/exporters/libvirt.yml
@@ -1,5 +1,7 @@
 applications:
   - prometheus
+classes:
+ - service.prometheus.support
 parameters:
   _param:
     prometheus_exporter_libvirt_port: 9177