Improper mechanism-realm configuration with saslauthenticationfactory/httpauthenticationfactory cli command

Issue

• When adding sasl authentication factory with below cli command, we get an issue where mechanism-realm realm-name="testrealm" is created outside the context of mechanism mechanism-name="PLAIN", same thing observed also for http-authentication-factory:

$  saslauthenticationfactory add --name=testauth --sasl-server-factory=testfact --security-domain=testdom --mechanism-configurations=[{mechanism-name=PLAIN,mechanism-realm-configurations=[{realm-name=testrealm}]}]

#Result:
                    <mechanism-configuration>
                        <mechanism mechanism-name="PLAIN"/>
                        <mechanism>
                            <mechanism-realm realm-name="testrealm"/>
                        </mechanism>