Fix the definition of the remote_collector service

This change removes unneeded plugins and adds the ones that are
otherwise required.
diff --git a/metadata/service/remote_collector/single.yml b/metadata/service/remote_collector/single.yml
index d0b6420..e141799 100644
--- a/metadata/service/remote_collector/single.yml
+++ b/metadata/service/remote_collector/single.yml
@@ -6,3 +6,4 @@
   heka:
     remote_collector:
       enabled: true
+      influxdb_time_precision: ms