GRAILS-8978: Respect grails.views.gsp.htmlcodec configuration

Commit 5037e65a04e33d9b6cd9cf7be8ca5921c4816de4 intended for the grails.views.gsp.htmlcodec setting to take effect. This commit fixes the implementation so that setting is respected.

https://jira.grails.org/browse/GRAILS-8978
what was the motivation in using the static holder version rather than GrailsApplicationAware?