How do we confirm that upgrading to AES-256 GCM encryption succeeded?

[jim_kubicek-162]

We’ve followed the instructions outlined here. The encryption migration process returned success, we were able to successfully start the Looker instance, so it looks like it worked, however the database appears to still be unencrypted. Looking through the logs during migration we see that a value `crypt_canary_gcm` was inserted into the `SETTINGS` table, but when we query the Looker DB, we don’t see that value present. 

Is there anything else we should be looking at to confirm that the  migration to GCM was successful? Is there anything else we should be doing to enable DB encryption?