fix: add error handling to get-service-names.sh

[zhumin8]

This script lacked error handling, causing it to fail when modules like java-marketingplatformadminapi
See context in doc

This fix is manually tested and can get a peek of data with

SELECT * FROM `cloud-java-metrics.client_library_versions.cloud_java_client_library_release_dates` 
WHERE TIMESTAMP_TRUNC(_PARTITIONTIME, DAY) = TIMESTAMP("2025-03-27") LIMIT 1000

For longer term, consider adding tests and/or refactoring.