set application cred env var

Author: mpeddada1

.kokoro/build.sh

@@ -74,7 +74,7 @@ graalvmA)
     # Run Unit and Integration Tests with Native Image
     echo "HELLOOOO"
     bash .kokoro/populate-secrets.sh
-    export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/${GOOGLE_APPLICATION_CREDENTIALS}
+    export GOOGLE_APPLICATION_CREDENTIALS="${KOKORO_GFILE_DIR}/secret_manager/java-it-service-account"
 #    if [[ ! -z "${GOOGLE_APPLICATION_CREDENTIALS}" && "${GOOGLE_APPLICATION_CREDENTIALS}" != /* ]]; then
 #      echo "HELLO1"
 #      export GOOGLE_APPLICATION_CREDENTIALS=$(realpath ${KOKORO_GFILE_DIR}/${GOOGLE_APPLICATION_CREDENTIALS})