storage: API fixups
storage: API fixups

github.com/containers/image/types.ImageReference.NewImage() can take a
*github.com/containers/image/types.SystemContext now, so pass it one if
pkg/storage/imageService.CanPull() has one to give it.

Signed-off-by: Nalin Dahyabhai <f562fcb2a0b898bf0be1afc867ea92325d8f825f@redhat.com>

mikebrow/cri-o,rhatdan/cri-o,nalind/cri-o,mikebrow/cri-o,kubernetes-incubator/cri-o,14rcole/cri-o,mheon/cri-o,14rcole/cri-o,mikebrow/cri-o,vbatts/cri-o,kubernetes-incubator/ocid,rhatdan/cri-o,jwhonce/ocid,vbatts/cri-o,14rcole/cri-o,mheon/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,jwhonce/ocid,mikebrow/cri-o,vbatts/cri-o,kubernetes-incubator/cri-o,vbatts/cri-o,mheon/cri-o,kubernetes-incubator/ocid,mheon/cri-o,rhatdan/cri-o,14rcole/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,jwhonce/ocid,rhatdan/cri-o