Add drop_event support

This will allow to drop any log events from fluentd flow.
If log event contain key `drop_event` with any value (not empty)
it will be deleted.

Closes-Bug: PROD-16326
Change-Id: I63cbbe090de5117b991bae07ca42e26985b2cbcf
diff --git a/fluentd/label/default_output/drop_event.yml b/fluentd/label/default_output/drop_event.yml
new file mode 100644
index 0000000..295862c
--- /dev/null
+++ b/fluentd/label/default_output/drop_event.yml
@@ -0,0 +1,17 @@
+agent:
+  config:
+    label:
+      default_output:
+        filter:
+          drop_event:
+            tag: '**'
+            type: grep
+            exclude:
+              - name: drop_event
+                regexp: ^.+?$
+          remove_drop_event_key:
+            require:
+              - drop_event
+            tag: '**'
+            type: record_transformer
+            remove_keys: drop_event