We inadvertently used
kms.GetWrapper(ctx, am.ScopeId, kms.KeyPurposeDatabase)
which resulted in the use of a database key for an oplog entry.
See:
https://github.com/hashicorp/boundary/pull/3665/files#diff-bcf83b5283886c98fc45b6435fdc94d87d545b2768c6beac8acd14eb9d6b13f1
This fixes the issue with the missing "Database" purpose key when
we converted the oplog keys into their own tables.
We chosen to truncate the existing oplog entries to eliminate any
references to a Database kms key in existing oplog entries.