add variable filebeat_auth_enabled for possibility to disable sending auth logs

Change-Id: I2cc2f2c4bdebbdec1fab835e9c0df1f165b5fc9d

Author: razizov

elk_metrics_7x/roles/elastic_filebeat/templates/filebeat.yml.j2

@@ -28,7 +28,7 @@ filebeat.modules:
 
   # Authorization logs
   auth:
-    enabled: true
+    enabled: {{ filebeat_auth_enabled | default(true) | lower }}
 
     # Set custom paths for the log files. If left empty,
     # Filebeat will choose the paths depending on your OS.