Custom merge conflict message

We're in a situation where we have customized our git workflow, to the point that the merge conflict suggestions during pull requests do not match the reality of what a developer should do in the event of a merge conflict. We block pushes to our integration branches, we require that 1 extra user approves a pull request, and we require 1 good build from our Build Agents.
This has us in a situation where we cannot follow the instructions in the merge conflict message that stash delivers, which ends up confusing new engineers, and causing issues for those that don't develop on shared projects all the time.

We would like to customize the message to something that suits our workflow better.