Dashboards tabs: If trying to navigate to non existing tab with url, default to the first tab (#101784)

* if tab does from url does not exist default to 0

* fix lint

public/app/features/dashboard-scene/scene/layout-tabs/TabsLayoutManager.tsx

@@ -56,7 +56,12 @@ export class TabsLayoutManager extends SceneObjectBase<TabsLayoutManagerState> i
       return;
     }
     if (typeof values.tab === 'string') {
-      this.setState({ currentTabIndex: parseInt(values.tab, 10) });
+      const tabIndex = parseInt(values.tab, 10);
+      if (this.state.tabs[tabIndex]) {
+        this.setState({ currentTabIndex: tabIndex });
+      } else {
+        this.setState({ currentTabIndex: 0 });
+      }
     }
   }
 

public/app/features/dashboard-scene/scene/layout-tabs/TabsLayoutManagerRenderer.tsx

@@ -12,8 +12,8 @@ import { TabsLayoutManager } from './TabsLayoutManager';
 
 export function TabsLayoutManagerRenderer({ model }: SceneComponentProps<TabsLayoutManager>) {
   const styles = useStyles2(getStyles);
-  const { tabs, currentTabIndex } = model.useState();
-  const currentTab = tabs[currentTabIndex];
+  const { tabs } = model.useState();
+  const currentTab = model.getCurrentTab();
   const { layout } = currentTab.useState();
   const dashboard = getDashboardSceneFor(model);
   const { isEditing } = dashboard.useState();