1. What is the nature and description of the request?Customer want to set the SCM branch for project update via REST API. Currently this functionality does not exist, additionally in the ansible.controller.project_update module this parameter is not supported.

https://docs.ansible.com/automation-controller/latest/html/controllerapi/api_ref.html#/Projects/Projects_projects_update_read
https://console.redhat.com/ansible/automation-hub/repo/published/ansible/controller/content/module/project_update/

1. Why does the customer need this? (List the business requirements here)
2. How would you like to achieve this? (List the functional requirements here)
3. List any affected known dependencies: Doc, UI etc..
4. Github Link if any  
   https://github.com/ansible/awx/issues/13986