Fix "Update Network: should delete added rpc url for exis..." flaky tests

https://app.circleci.com/pipelines/github/MetaMask/metamask-extension/101672/workflows/e38c0e67-5e2a-4920-b83c-4fdf588ddd2f/jobs/3785936/tests

Build - Regular Browser - Firefox Test Scenario - Update Network: should delete added rpc url for existing network Test Path - /test/e2e/tests/network/update-network.spec.ts

ElementClickInterceptedError: Element <button class="mm-box mm-picker-network multichain-app-header__contents__network-picker mm-box--margin-2 mm-box--padding-right-4 mm-box--padding-left-2 mm-box--display-none mm-box--sm:display-flex mm-box--gap-2 mm-box--align-items-center mm-box--background-color-background-alternative mm-box--rounded-pill"> is not clickable at point (218,125) because another element <div class="popover-bg"> obscures it
  (Ran on CircleCI Node 16 of 24, Job test-e2e-firefox)
    at Object.throwDecodedError (node_modules/selenium-webdriver/lib/error.js:524:15)
    at parseHttpResponse (node_modules/selenium-webdriver/lib/http.js:601:13)
    at Executor.execute (node_modules/selenium-webdriver/lib/http.js:529:28)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async thenableWebDriverProxy.execute (node_modules/selenium-webdriver/lib/webdriver.js:745:17)
    at async element.click (test/e2e/webdriver/driver.js:94:9)
    at async Driver.clickElement (test/e2e/webdriver/driver.js:579:9)
    at async /home/circleci/project/test/e2e/tests/network/update-network.spec.ts:2:6316
    at async withFixtures (test/e2e/helpers.js:217:5)
    at async Context.<anonymous> (test/e2e/tests/network/update-network.spec.ts:2:4536)

MetaMask / metamask-extension

Fix "Update Network: should delete added rpc url for exis..." flaky tests #27334