Fix fluentd tag propagation (#1385)

Author: deliahu

manager/manifests/fluentd.yaml

@@ -145,7 +145,7 @@ data:
         region "#{ENV['AWS_REGION']}"
         log_group_name_key group_name
         log_stream_name_key stream_name
-        log_group_aws_tags "${CORTEX_TAGS_JSON}"
+        log_group_aws_tags ${CORTEX_TAGS_JSON}
         remove_log_stream_name_key true
         remove_log_group_name_key true
         auto_create_stream true