Add SLACK_CHANNELS parameter

PRODX-38825
PRODX-38876

Change-Id: Iae94c917a05c7dcf6252831a68e8d3ffd5530a43
diff --git a/src/com/mirantis/mk/KaasUtils.groovy b/src/com/mirantis/mk/KaasUtils.groovy
index c7a600c..d6a9250 100644
--- a/src/com/mirantis/mk/KaasUtils.groovy
+++ b/src/com/mirantis/mk/KaasUtils.groovy
@@ -1529,6 +1529,7 @@
         'FORCE': '-force',
         'HELM_CDN_DOMAIN': '-helm-cdn-domain',
         'SLACK_CHANNEL': '-slack-channel',
+        'SLACK_CHANNELS': '-slack-channels',
         'SLACK_USER': '-slack-user',
         'SOURCE_REGISTRY': '-src-repo',
         'SOURCE_REGISTRY_TYPE': '-src-repo-type',