Move to the new Kubernetes image repository

Problem: The Kubernetes project is moving its images from the k8s.gcr.io
registry to the registry.k8s.io registry and our project relies on one
of the images being moved. More information can be found here:
kubernetes/k8s.io#4780

Solution: Update the referenced image to point to the same image hosted
at the new registry.

Signed-off-by: Alexander Greene <greene.al1991@gmail.com>

test/tools/imageregistry/daemonset.yaml

@@ -43,4 +43,4 @@ spec:
           privileged: true
       containers:
       - name: wait
-        image: k8s.gcr.io/pause:3.1
+        image: registry.k8s.io/pause:3.1