Add properties file for cos-docker-validation test job

test/e2e_node/jenkins/docker_validation/cos-docker-validation.properties

+GCI_IMAGE_PROJECT=cos-docker-validation
+GCI_IMAGE_FAMILY=validation-test
+GCI_IMAGE=$(gcloud compute images describe-from-family ${GCI_IMAGE_FAMILY} --project=${GCI_IMAGE_PROJECT} --format="value(name)")
+GCI_CLOUD_INIT=test/e2e_node/jenkins/gci-init.yaml
+
+GCE_HOSTS=
+GCE_IMAGES=${GCI_IMAGE}
+GCE_IMAGE_PROJECT=${GCI_IMAGE_PROJECT}
+GCE_ZONE=us-central1-f
+GCE_PROJECT=node-cos-docker-validation
+# user-data is the GCI cloud init config file.
+GCE_INSTANCE_METADATA="user-data<${GCI_CLOUD_INIT},gci-update-strategy=update_disabled"
+CLEANUP=true
+GINKGO_FLAGS='--skip="\[Flaky\]|\[Serial\]"'
+TIMEOUT=1h