Fix flaky test from gr-change-list

Missing done for async tests

Change-Id: I02ca997d768773f0bbcc60e92532c19e5f4c2a38
(cherry picked from commit d027c78f4922a136c7cab52c0a5207cec9ada65f)
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html
index 395769b..87b1665 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html
@@ -497,7 +497,7 @@
 
     teardown(() => { sandbox.restore(); });
 
-    test('keyboard shortcuts', () => {
+    test('keyboard shortcuts', done => {
       element.selectedIndex = 0;
       element.sections = [
         {
@@ -560,6 +560,7 @@
         MockInteractions.pressAndReleaseKeyOn(element, 82); // 'r'
         assert.equal(change.reviewed, false,
             'Should mark change as unreviewed');
+        done();
       });
     });