Bugfix failtest field in the expectations files

Some errors have been detected when updating the expectations.

First of all, and what triggers everything, is that the implementation has changed the formatting by mistake. For example, the implementation writes a list in the field of the CSV for the test result when the correct content is only the name of the test result.

This bug has also produced an example of a flake reported as a test fail. When we collect results from the pipeline execution, we only collect information from what has failed. So, if it only fails once, it is because it has succeeded another. And this is what we define as a flake.