Fix click toggle on gr-result-row summary

Currently the handler is toggleExpanded that has argument setExpanded.
When called on click, first argument is the event, so setExpanded ends
up being an object instead boolean|undefined. This leads to incorrect
behaviour.

Google-Bug-Id: b/349144992
Release-Notes: skip
Change-Id: I5f00f9306694e729e72df0a729eb97ee00d894fa
(cherry picked from commit 06a16afc5f1337b6a53b2a4d304183fffe161153)
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-results.ts b/polygerrit-ui/app/elements/checks/gr-checks-results.ts
index 72d3268..b94aa52 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-results.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-results.ts
@@ -486,7 +486,7 @@
     return html`
       <!-- The &nbsp; is for being able to shrink a tiny amount without
        the text itself getting shrunk with an ellipsis. -->
-      <div class="summary" @click=${this.toggleExpanded} title=${text}>
+      <div class="summary" @click=${this.toggleExpandedClick} title=${text}>
         ${text}&nbsp;
       </div>
     `;
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
index a349b58..22c2940 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
@@ -123,6 +123,22 @@
     `
     );
   });
+
+  test('click summary, toggle expand', async () => {
+    element.isExpandable = true;
+    await element.updateComplete;
+    assert.isFalse(element.isExpanded);
+
+    const summaryDiv: HTMLElement =
+      element.shadowRoot!.querySelector('.summary')!;
+    summaryDiv.click();
+    await element.updateComplete;
+    assert.isTrue(element.isExpanded);
+
+    summaryDiv.click();
+    await element.updateComplete;
+    assert.isFalse(element.isExpanded);
+  });
 });
 
 suite('gr-checks-results test', () => {