Adding config for new validator also auto-exports "required/Html" validator config

When a new validator is configured, auto-export also exports the configuration of the "required/Html" validator. Which is weird, since that validator is bootstrapped by the system itself and should not be auto-exported.

As a result, the repository does not start again when bootstrapped cleanly.

Steps to reproduce:

1: Create a 13.3.0-SNAPSHOT archetype:

mvn org.apache.maven.plugins:maven-archetype-plugin:2.4:generate -DarchetypeRepository=https://maven.onehippo.com/maven2 -DarchetypeGroupId=org.onehippo.cms7 -DarchetypeArtifactId=hippo-project-archetype -DarchetypeVersion=13.3.0-SNAPSHOT

2: Build and start

cd myproject
mvn clean verify
mvn -Pcargo.run -Drepo.path=storage 

3: Login to the Console and add a new validator. For example reuse the 'escaped' validator class but call it 'bla':

/hippo:configuration/hippo:modules/validation/hippo:moduleconfig/bla:
  jcr:primaryType: hipposys:moduleconfig
  hipposys:className: org.onehippo.cms.services.validation.validator.EscapedHtmlValidator

4: Stop the CMS.

5: Check that auto-export created the file hcm-config/configuration/modules/validation.yaml

Expected: validation.yaml only contains the new 'bla' validator
Actual: validation.yaml also contains the 'required/Html' validator

The worst part:
6: Rebuild the project

mvn clean verify 

7: Restart with a clean repository

rm -rf storage
mvn -Pcargo.run -Drepo.path=storage 

8: Notice how the CMS fails to start