When migrating from Casper to Puppeteer, some tests
were missed for adding log-out calls at the end.
This commit adds log-out calls to those missed tests.
Also, As we are resetting the test database after each
run (from 99f8be6a12) it will better to log out because we are
not resetting Tornado's internal state. It'd help us prevent
any future flakes.
When typing the password in Firefox,
it shows a "Not Secure" warning which was
hiding the "#get_api_key_button". You can see
the screenshot of it in #17136.
This commit fixes that issue by focusing on the button.
This commit works around an issue with Puppeteer tests on Firefox
where `page.url()` does not show the URL fragment, by adding a
temporary function that solves the issue.
