This changes the type of the sourceFormat field from string to the defined type in the RSync spec. This reduces the number of type conversions required and makes the code more self documenting.
Needs approval from an approver in each of these files:
- ~~[OWNERS](https://github.com/GoogleContainerTools/kpt-config-sync/blob/main/OWNERS)~~ [karlkfi]
Approvers can indicate their approval by writing `/approve` in a comment
Approvers can cancel approval by writing `/approve cancel` in a comment
This changes the type of the sourceFormat field from string to the defined type in the RSync spec. This reduces the number of type conversions required and makes the code more self documenting.