Is it possible to have both Sqlcipher 1.5 and sqlcipher 1.6 libraries in the same program in order to be able to decrypt an encrypted database in 1.5 and rewrite the data in the database in 1.6 without updating the application.
If the database is stored in the external storage then you can make another app with SQLCipher v1.5 that exports the data to a regular database. Make an option in the upgraded app to import the data back with SQLCipher v1.6.