luna-sysmgr: install platform-specific icon layout config

Open-webOS-DCO-1.0-Signed-off-by: Josh Palmer <jpalmerwatkins@me.com>
Open-webOS-DCO-1.0-Signed-off-by: Tom King <ka6sox@gmail.com>
Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>