message: Fix typo in test environment check.
diff: @@ -86,7 +86,7 @@ run_all_linux_tests() {
  run_linux_tests "python"
  local -a MANUAL_TOOLS_TARGETS
  - if [[ -n "{KOKORO_ROOT}" ]]; then
  + if [[ -n "${KOKORO_ROOT}" ]]; then
  MANUAL_TOOLS_TARGETS+=(
  "//testing/cc:aws_kms_aead_test"
  "//testing/cc:gcp_kms_aead_test"
  