Add simplest happy path end-to-end test of Monitor feature

Summary

As a first pass at adding more integration tests for Monitor features, we want to build out one, simple end-to-end test. The larger issue is https://gitlab.com/gitlab-org/gitlab-ce/issues/58407

Improvements

We need to:

1. Identify the easiest happy path to test
2. Talk to Mek and/or Dylan about what already exists in the QA test suite and how we should expand on it.
3. Deliver one test to the QA test suite that exercises on of our features. This does not necessarily need to be a Debugging & Health feature. It could be APM.