LPS-46781 - Dockbar Add Content popout menu stays open after closing left Dockbar

Hi Jon,

Attached is an update for https://issues.liferay.com/browse/LPS-46781.

This is a regression bug which I found to start occurring at commit 2fe582f2c83f9c8d40df775e03b2ac391ef73434.  

The root of this issue is the 'addContent' component is being destroyed before the popover hide handler is fired. In ee-6.2.x the bug does not occur because the 'addContent' component is not destroyed when the add panel is closed.  My fix will explicitly call the popover.destroy method from the 'addContentPreview' destructor.

Please let me know if there are any issues.

Thanks!