settings: Fix flaky test.

We wait for settings overlay to be fully visible before
running rest of the tests. Without this, tests were flaky due
to settings overlay not being present when running tests.

web/e2e-tests/settings.test.ts

@@ -30,6 +30,8 @@ async function open_settings(page: Page): Promise<void> {
         page_url.includes("/#settings/"),
         `Page url: ${page_url} does not contain /#settings/`,
     );
+    // Wait for settings overlay to open.
+    await page.waitForSelector("#settings_overlay_container", {visible: true});
 }
 
 async function close_settings_and_date_picker(page: Page): Promise<void> {