Adds a button to tasks that a person has to start, for users who may build them: the jobs listed in an upstream job's "Delivery Pipeline manual step" post-build action, or in its "Build other projects (manual step)" action when the Build Pipeline plugin is installed. The button appears once the upstream build has finished and starts the job with that build's parameters. Pipeline runs waiting at an input step get a button that lets them proceed, whether or not this is enabled.