chore: update sa for loading secrets (googleapis#8729)

internal/kokoro/populate-secrets.sh

@@ -15,23 +15,22 @@
 
 set -eo pipefail
 
-function now { date +"%Y-%m-%d %H:%M:%S" | tr -d '\n' ;}
-function msg { println "$*" >&2 ;}
-function println { printf '%s\n' "$(now) $*" ;}
-
+function now { date +"%Y-%m-%d %H:%M:%S" | tr -d '\n'; }
+function msg { println "$*" >&2; }
+function println { printf '%s\n' "$(now) $*"; }
 
 # Populates requested secrets set in SECRET_MANAGER_KEYS from service account:
 # kokoro-trampoline@cloud-devrel-kokoro-resources.iam.gserviceaccount.com
 SECRET_LOCATION="${KOKORO_GFILE_DIR}/secret_manager"
 msg "Creating folder on disk for secrets: ${SECRET_LOCATION}"
 mkdir -p ${SECRET_LOCATION}
-for key in $(echo ${SECRET_MANAGER_KEYS} | sed "s/,/ /g")
-do
+for key in $(echo ${SECRET_MANAGER_KEYS} | sed "s/,/ /g"); do
   msg "Retrieving secret ${key}"
   docker run --entrypoint=gcloud \
     --volume=${KOKORO_GFILE_DIR}:${KOKORO_GFILE_DIR} \
     gcr.io/google.com/cloudsdktool/cloud-sdk \
     secrets versions access latest \
+    --credential-file-override=${KOKORO_GFILE_DIR}/kokoro-trampoline.service-account.json \
     --project cloud-devrel-kokoro-resources \
     --secret ${key} > \
     "${SECRET_LOCATION}/${key}"