Fix logging to Kafka on ONOS 2.2

Need ONOS with Karaf>4.2.8 to support logging on Kafka with KafkaAppender of
log4j2.

Change-Id: I6f53329dcf367c93f7913d363c3048e80c2c5392
diff --git a/onos/values.yaml b/onos/values.yaml
index 5a2d46b..58a5d87 100644
--- a/onos/values.yaml
+++ b/onos/values.yaml
@@ -25,18 +25,12 @@
     tag: '{{ .Chart.AppVersion }}'
     pullPolicy: 'Always'
 
-  # keep in sync with: https://github.com/helm/charts/blob/master/stable/filebeat/values.yaml
-  log_agent:
-    repository: docker.elastic.co/beats/filebeat-oss
-    tag: 6.4.2
-    pullPolicy: IfNotPresent
-
 global:
   registry: ''
 
-log_agent:
+kafka_logging:
   enabled: True
-  kafka_brokers: ['cord-kafka:9092']
+  brokers: ['cord-kafka:9092']
 
 nameOverride: ''
 fullnameOverride: ''