add cp to configmap-registry image

Author: Jeff Peeler

configmap-registry.Dockerfile

@@ -1,8 +1,10 @@
 FROM quay.io/operator-framework/upstream-registry-builder:latest as builder
+FROM busybox as userspace
 
 FROM scratch
 COPY --from=builder /build/bin/configmap-server /bin/configmap-server
 COPY --from=builder /build/bin/opm /bin/opm
+COPY --from=userspace /bin/cp /bin/cp
 COPY --from=builder /bin/grpc_health_probe /bin/grpc_health_probe
 EXPOSE 50051
 ENTRYPOINT ["/bin/configmap-server"]