Use DEB pkgs for Fluentd plugins

On mirror.fuel-infra.org there is a package
td-agent-additional-plugins which ships all the additional
fluentd gems (plugins and its deps).

Change-Id: Iaf2cfe9e2c32bf9cb9c165615b3728c7d51f7519
Related-Bug: PROD-17532
diff --git a/kubernetes/meta/fluentd.yml b/kubernetes/meta/fluentd.yml
index 6db50b3..b2a27dc 100644
--- a/kubernetes/meta/fluentd.yml
+++ b/kubernetes/meta/fluentd.yml
@@ -12,7 +12,7 @@
 agent:
   plugin:
     fluent-plugin-kubernetes_metadata_filter:
-      gem: ['fluent-plugin-kubernetes_metadata_filter']
+      deb: ['td-agent-additional-plugins']
   config:
     label:
       docker: