S2I build failure when assembly plugin is used

If pom file in git project contains maven-assembly-plugin and some dependencies then S2I build fails.
The failure is caused by scripts [1] [2] expecting "${JAR}/META-INF/maven" folder to contain only one pom.xml file. In case the folder contains several pom.xml files (which are brought by maven-assembly-plugin) then scripts don't detect artifact as jar file and don't install it to local Maven registry.

[1] https://github.com/jboss-container-images/jboss-kie-modules/blob/master/jboss-kie-kieserver/added/launch/kieserver-install.sh#L61
[2] https://github.com/jboss-container-images/jboss-kie-modules/blob/master/os.kieserver.launch/added/kieserver-install.sh#L33