Resolve RSpec/UndescriptiveLiteralsDescription in MR base service spec

Arpit Tripathirequested to merge
gitlab-community/gitlab-org/gitlab:fix/rspec-undescriptive-description into master

This MR resolves an `RSpec/UndescriptiveLiteralsDescription` RuboCop offense in the Merge Request base service spec by standardizing the description format for the `#create_pipeline_for` method.


fixes #592383 (closed)

Merge request reports