Provide clear notifications about first Auto DevOps pipelines that failed
Description
Auto DevOps could be on by default for any project, with an instance-wide setting.
When a new project is created, it could be possible it will fail pipelines forever, because it is just a specific project that Auto DevOps doesn't support. In this case, after a few failures, Auto DevOps will be suspended automatically (https://gitlab.com/gitlab-org/gitlab-ce/issues/39923).
Before it happens, users will receive notifications for failed pipelines. They could hard to understand, since they are exactly as any other regular failure notification.
Proposal
Improve the failure notifications for Auto DevOps pipelines when Auto DevOps is on by default, but still "trying" to work for the project (failures before the auto-disable feature is triggered).
The notifications should explicitly say that Auto DevOps tried, but failed. Later, if Auto DevOps succeeded and then failed again, the notification will be the standard one, as the "trial" phase was already over.