Update layout builder tests and set new config

Problem/Motivation

Follow up from ✨ Prevent auto-adding new fields to LB layouts Needs review we need to set the default value to FALSE for new sites and fix the failing tests

Steps to reproduce

NA

Proposed resolution

Set default value for new setting to FALSE and fix tests

Remaining tasks

Implement
Review

User interface changes

NA

API changes

NA

Data model changes

NA

Release notes snippet

NA