test: confirm behavior of GraalVM 25

Author: diegomarquezp

.kokoro/build.sh

@@ -110,6 +110,9 @@ integration-cloud-staging)
     ;;
 graalvm)
     # Run Unit and Integration Tests with Native Image.
+	curl -s "https://get.sdkman.io" | bash
+    sdk install java 25-graalce
+    java -version
     mvn -B ${INTEGRATION_TEST_ARGS} -ntp -Pnative -Penable-integration-tests test "-Dtest=com.google.cloud.spanner.jdbc.it.**"
     RETURN_CODE=$?
     ;;