Set DOCKER_REGISTRY in the rest of the buildscripts

Author: sergiitk

test/kokoro/psm-security.sh

@@ -19,6 +19,7 @@ set -eo pipefail
 readonly GITHUB_REPOSITORY_NAME="grpc-go"
 readonly TEST_DRIVER_INSTALL_SCRIPT_URL="https://raw.githubusercontent.com/${TEST_DRIVER_REPO_OWNER:-grpc}/psm-interop/${TEST_DRIVER_BRANCH:-main}/.kokoro/psm_interop_kokoro_lib.sh"
 ## xDS test server/client Docker images
+readonly DOCKER_REGISTRY="us-docker.pkg.dev"
 readonly SERVER_IMAGE_NAME="us-docker.pkg.dev/grpc-testing/psm-interop/go-server"
 readonly CLIENT_IMAGE_NAME="us-docker.pkg.dev/grpc-testing/psm-interop/go-client"
 readonly FORCE_IMAGE_BUILD="${FORCE_IMAGE_BUILD:-0}"

test/kokoro/xds_url_map.sh

@@ -19,6 +19,7 @@ set -eo pipefail
 readonly GITHUB_REPOSITORY_NAME="grpc-go"
 readonly TEST_DRIVER_INSTALL_SCRIPT_URL="https://raw.githubusercontent.com/${TEST_DRIVER_REPO_OWNER:-grpc}/psm-interop/${TEST_DRIVER_BRANCH:-main}/.kokoro/psm_interop_kokoro_lib.sh"
 ## xDS test client Docker images
+readonly DOCKER_REGISTRY="us-docker.pkg.dev"
 readonly CLIENT_IMAGE_NAME="us-docker.pkg.dev/grpc-testing/psm-interop/go-client"
 readonly FORCE_IMAGE_BUILD="${FORCE_IMAGE_BUILD:-0}"