Handle ActiveRecord attributes inheriting from EncryptedAttributeType with custom sigs

[alex-tan]

Motivation

We have a custom type inheriting from ActiveRecord::Encryption::EncryptedAttributeType with a deserialize method that has a sig specifying the return type.

Previously the column type would hit the ActiveRecord::Type::String branch of type_for_activerecord_value and return ::String because ActiveRecord::Encryption::EncryptedAttributeType inherits from ActiveRecord::Type::String.

Implementation

I added a case statement for ActiveRecord::Encryption::EncryptedAttributeType to type_for_activerecord_value.

Tests

I have.