Add validation of AutoDevops project templates
Problem to solve
We currently ship a handful of project templates with GitLab, which serve as a quickstart for various languages to easily try out Auto DevOps and related features.
We currently however, don't automatically test these, so if we break something during the course of development we may not know until users report it. Keep in mind that the features of Auto DevOps span across multiple stages and many features, so there could easily be changes that the team managing the templates is not aware of.
We should add CI test for our project templates, so that we can be sure that they have not been unintentionally broken during the course of development. This could also reduce the amount of testing required when a change that impacts ADO is being developed.
For example, we could add a test in GitLab QA to create a project from the template and run the first pipeline and ensure it succeeds.