Dismiss barracuda's feature discovery message when it is closed.

Currently, the message will be only dismissed by clicking on the "Dismiss" button. However, it could be closed in some other ways, e.g., clicking on the rest of the page or auto-hiding. In such way, the dialog is not actually dismissed and will come up again next time which causes confusion to the user.

At the moment, we cannot force the aui inline-dialog to stay visible until it is closed programmatically, so we cannot implement the correct behaviour for a feature discovery message now. The fix is done on https://ecosystem.atlassian.net/browse/AUI-1260 and will be in aui-5.1

However, for the time being, we will just dismiss the message when it is closed, whichever way it is used to close the message.