Whether to enable live thumbnail for this page.
When set to TRUE, the page's thumbnail in class@TabOverview will update immediately when the page is redrawn or resized.
If it's set to FALSE, the thumbnail will only be live when the page is selected, and otherwise it will be static and will only update when adw.tab_page.TabPage.invalidateThumbnail or adw.tab_view.TabView.invalidateThumbnails is called.
Set liveThumbnail property.