[Search Sessions][Dashboard] Clear search session when navigating from dashboard route (#89749)

Author: Dosant

src/plugins/dashboard/public/application/dashboard_app.tsx

@@ -265,6 +265,13 @@ export function DashboardApp({
     };
   }, [dashboardStateManager, dashboardContainer, onAppLeave, embeddable]);
 
+  // clear search session when leaving dashboard route
+  useEffect(() => {
+    return () => {
+      data.search.session.clear();
+    };
+  }, [data.search.session]);
+
   return (
     <div className="app-container dshAppContainer">
       {savedDashboard && dashboardStateManager && dashboardContainer && viewMode && (

x-pack/test/send_search_to_background_integration/tests/apps/dashboard/async_search/send_to_background.ts

@@ -96,6 +96,10 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       // should leave session state untouched
       await PageObjects.dashboard.switchToEditMode();
       await searchSessions.expectState('restored');
+
+      // navigating to a listing page clears the session
+      await PageObjects.dashboard.gotoDashboardLandingPage();
+      await searchSessions.missingOrFail();
     });
   });
 }