Enable telegraf internal plugin everywhere

Change-Id: I95da01268aab720e454080a1965bf19e37ebf6ec
Related-PROD: PROD-30675
(cherry picked from commit ee48ad626e63f46c0e19072e4062b9dcc3d118d5)
diff --git a/telegraf/agent/init.yml b/telegraf/agent/init.yml
index 64ef566..213d3ba 100644
--- a/telegraf/agent/init.yml
+++ b/telegraf/agent/init.yml
@@ -1,5 +1,6 @@
 classes:
 - service.telegraf.agent
+- system.telegraf.agent.input.internal
 - system.telegraf.agent.input.http_listener
 - system.telegraf.agent.output.prometheus_client
 - system.telegraf.sudo
diff --git a/telegraf/agent/input/internal.yml b/telegraf/agent/input/internal.yml
new file mode 100644
index 0000000..aba90c8
--- /dev/null
+++ b/telegraf/agent/input/internal.yml
@@ -0,0 +1,5 @@
+parameters:
+  telegraf:
+    agent:
+      input:
+        internal: