Updating ose-csi-snapshot-controller builder & base images to be cons…

…istent with ART

Reconciling with https://github.com/openshift/ocp-build-data/tree/0b997d0add07947c7ca65baa44901a2d113fd0e9/images/ose-csi-snapshot-controller.yml

Dockerfile.snapshot-controller.openshift.rhel7

@@ -1,8 +1,8 @@
-FROM registry.svc.ci.openshift.org/ocp/builder:rhel-8-golang-1.15-openshift-4.6 AS builder
+FROM registry.svc.ci.openshift.org/ocp/builder:rhel-8-golang-openshift-4.7 AS builder
 WORKDIR /go/src/github.com/kubernetes-csi/external-snapshotter
 COPY . .
 RUN make build
 
-FROM registry.svc.ci.openshift.org/ocp/4.6:base
+FROM registry.svc.ci.openshift.org/ocp/4.7:base
 COPY --from=builder /go/src/github.com/kubernetes-csi/external-snapshotter/bin/snapshot-controller /usr/bin/
 ENTRYPOINT ["/usr/bin/snapshot-controller"]