cleanup: fix shellcheck warnings (#1467)

Author: coryan

ci/kokoro/docker/download-cache.sh

@@ -61,7 +61,7 @@ activate_service_account_keyfile "${KEYFILE}"
 
 echo "================================================================"
 log_normal "Downloading build cache ${CACHE_NAME} from ${CACHE_FOLDER}"
-env CLOUDSDK_ACTIVE_CONFIG_NAME=${GCLOUD_CONFIG} \
+env "CLOUDSDK_ACTIVE_CONFIG_NAME=${GCLOUD_CONFIG}" \
  gsutil -q cp "gs://${CACHE_FOLDER}/${CACHE_NAME}.tar.gz" "${HOME_DIR}"
 
 # Ignore timestamp warnings, Bazel has files with timestamps 10 years

ci/kokoro/docker/upload-cache.sh

@@ -62,7 +62,7 @@ cleanup() {
 
 create_gcloud_config
 activate_service_account_keyfile "${KEYFILE}"
-env CLOUDSDK_ACTIVE_CONFIG_NAME=${GCLOUD_CONFIG} \
+env "CLOUDSDK_ACTIVE_CONFIG_NAME=${GCLOUD_CONFIG}" \
  gsutil -q cp "${HOME_DIR}/${CACHE_NAME}.tar.gz" "gs://${CACHE_FOLDER}/"
 
 echo "================================================================"