Enable infra automation to add label on a Jira when a new PR is posted

https://cwiki.apache.org/confluence/display/INFRA/Git+-+.asf.yaml+features#Git.asf.yamlfeatures-Jiranotificationoptions

Currently we make use of the "link" feature. This does not send a notification to watchers, so I propose that we add the "comment" feature, so that a comment will also be sent, and watchers can find out about the availability of the PR.