check value of GOOGLE_APPLICATION_CREDENTIALS

Author: mpeddada1

.kokoro/build.sh

@@ -73,6 +73,7 @@ integration)
 graalvmA)
     # Run Unit and Integration Tests with Native Image
     bash .kokoro/populate-secrets.sh
+    echo $GOOGLE_APPLICATION_CREDENTIALS
     export GOOGLE_APPLICATION_CREDENTIALS="${KOKORO_GFILE_DIR}/secret_manager/java-it-service-account"
     mvn -B ${INTEGRATION_TEST_ARGS} -ntp -Pnative -Pnative-test test -pl 'oauth2_http'
     RETURN_CODE=$?