sdk: Revert Replace decorators before marshal

Revert patch Replace decorators before marshal

http://gerrit.ovirt.org/#/c/24131

Change-Id: Id18dc425c9bdff54cada4c62a3183fc729ae3b82
Bug-Url: https://bugzilla.redhat.com/1122546
Signed-off-by: Ravi Nori <rnori@redhat.com>