E2E test: add clipboard prefs to chromedriver

What does this MR do and why?

Resolves gitlab-org/quality/quality-engineering/team-tasks#3562 (closed)

When the web_ide_multi_domain FF was enabled in staging a test started failing as a dialog box asking for permission to read from clipboard was displayed:

https://gitlab.com/gitlab-org/gitlab/-/issues/536401

This MR enables the clipboard for our using chromedriver preferences.

References

How to set up and validate locally

QA_LOG_LEVEL=DEBUG QA_GITLAB_URL=https://gdk.test:3443 bundle exec rspec qa/specs/features/browser_ui/3_create/web_ide/upload_new_file_in_web_ide_spec.rb

I tested the above locally with Feature.enable :web_ide_multi_domain and also Feature.disable :web_ide_multi_domain

Also tested against staging when the FF was enabled in staging, (it's currently disabled in staging)

QA_GITLAB_URL=https://staging.gitlab.com bundle exec rspec qa/specs/features/browser_ui/3_create/web_ide/upload_new_file_in_web_ide_spec.rb

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.