Below is the scenario on the backup and restore scripts inadvertently overwrote the postgres password,
To fixed this issue, removed this file (postgresql.vault) from the backup.
Here is how we removed postgresql.vault from the backup tar file. This will have to happen for all 7.3.1 backup/restores.
You should be able to run this on the appliance before calling restore.
We can go ahead and restore using the new backup file solera-backup-Test-FIXED.tar.