Describe the bug

Default values for pControlTowerRegionsOnly are not consistent across stacks

To Reproduce

Steps to reproduce the behavior:

1. Try to deploy guardduty stack w/o specifying value for pControlTowerRegionsOnly
2. aws cloudformation deploy --template-file aws_sra_examples/easy_setup/templates/sra-easy-setup.yaml --stack-name sra-easy-setup --s3-bucket --capabilities CAPABILITY_NAMED_IAM --parameter-overrides pDeployGuardDutySolution=Yes pSRAAlarmEmail=
3. Custom resource lambda times out after 15min because it tries to deploy Guard duty in all AWS regions.

Expected behavior

Guardduty to be setup in Control Tower governed regions only.

Deployment Environment (please complete the following information)

• Deployment Framework [e.g. Customizations for Control Tower and CloudFormation StackSets]:
  CloudFormation StackSets
• Deployment Framework Version [e.g. 1.0, 2.0]:
  Main branch

Additional context

Fork with fix: https://github.com/wolfit/aws-security-reference-architecture-examples
Please advice how I can contribute or make a pull request