onRemovedFromFrontend
Called when a panel is removed from a panel and can not be reused again, preventing it from being shown in the system UI.
This method is called when a non-reusable panel is removed from Frontend.panels. This method is also called when a reusable panel is released through Frontend.releaseReusablePanel or Frontend.releaseReusablePanels. See Frontend.addPanel to add a panel as reusable.
This method may be called as a result of dismissing the panel, or due to other factors such as the frontend deciding that the panel is no longer relevant.
Be sure not to trigger new asynchronous calls that depend on this panel's lifecycle when overriding this method. E.g., IVI service calls. The panel's lifecycle will be destroyed here and the calls might not be processed.