This is a follow-up on T314852: SQL logical backups appear to be failing

The backups wasn't taken for more than a week but we never found out. This could probably have been spotted by adding more constraints to the alert we have that checks if a backup was taken.

AC

• the check that backups have been taken IS NOT only done by a single log output.

Useful links:

• https://github.com/wmde/wbaas-deploy/blob/main/tf/modules/monitoring/sql-backup-failure-alert.tf#L4
• https://cloud.google.com/blog/products/storage-data-transfer/guide-to-setting-up-monitoring-for-object-creation-in-cloud-storage

Useful metrics:

• storage.googleapis.com/storage/total_byte_seconds (resource type: gcs_bucket)
• storage.googleapis.com/storage/total_bytes (resource type: gcs_bucket)