sdk: Revert Replace decorators before marshal

Revert patch Replace decorators before marshal

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

Change-Id: I5da35cbf75b6e29f5c5b4a79bd07d757691d5de1
Bug-Url: https://bugzilla.redhat.com/1122546
Signed-off-by: Ravi Nori <rnori@redhat.com>