Since fuse 7.8 on karaf is using camel 2.23.x which was originally for sprng-boot 2 only, AS2 component is not usable for Karaf.
There are few years old changes. For example, I am not able to use any other package than org.apache.camel.* with old version 2.18.3
In version 2.21.x AS2 component worked, so it could be used as example for changes: https://github.com/jboss-fuse/camel/blob/2.21.x.redhat-7-x/components/camel-as2/camel-as2-component/pom.xml