v1 objects reference `manifest.ObjectHeader` instead of `ObjectHeader`

[kenfinnigan]

Summary

manifest.ObjectHeader is used as the header object for v1 objects, where the struct only contains APIVersion and not Kind or Metadata.

v1alpha objects correctly use the version specific ObjectHeader which does include Kind and Metadata.

Possible fixes

Change v1 objects to use ObjectHeader instead of manifest.ObjectHeader.

I will submit a PR shortly with such a change