fix(list): fix strong focus first keyboard nav

fixes an issue where first keyboard navigation would not show strong focus because event listeners flush the event queue and the keyboard event doesn't reach window before focus is called

PiperOrigin-RevId: 518731054

list/lib/list.ts

@@ -13,6 +13,7 @@ import {ClassInfo, classMap} from 'lit/directives/class-map.js';
 import {ifDefined} from 'lit/directives/if-defined.js';
 
 import {ariaProperty} from '../../decorators/aria-property.js';
+import {keydownHandler} from '../../focus/strong-focus.js';
 import {ARIARole} from '../../types/aria.js';
 
 import {ListItem} from './listitem/list-item.js';
@@ -129,6 +130,7 @@ export class List extends LitElement {
       activeItemRecord.item.active = false;
     }
 
+    keydownHandler(event);
     event.preventDefault();
 
     switch (key) {