E2E Test for product analytics ruby sdk events

What does this MR do and why?

• Adding a test for Product Analytics to check that events from Ruby SDK are processed and shown on Product Analytics dashboards. This test is to be run only for product-analytics/devkit for now. This test is needed to verify events from Ruby SDK are sent to Product Analytics and precessed successfully by its pipelines.
• Added a page refresh before going to product analytics set up due to known issue 404 error on first attempt to setup product analytics.
• Refactoring to use existing e2e flow for product analytics setup for previously added Browser SDK test.

Successful execution in Product Analytics devkit pipeline using gitlab-ee-qa docker image built from this branch - https://gitlab.com/gitlab-org/analytics-section/product-analytics/devkit/-/jobs/6951283223

MR acceptance checklist

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

Screenshots or screen recordings

Successful test execution screenshot:

How to set up and validate locally

Not required. Please refer to this guide if you like to run the test locally.

Note the following:

• PA_COLLECTOR_HOST variable should be set to http://caddy:80.
• For RubySdkApp class set @host_name = 'localhost' when running locally against GKD.