Cleanup: Remove unnecessary dash escape when building docker container name

We don't need this dash escape since they are not valid name for Container and Pod. Modified test to reflect the changes, and also removed two test cases since they are not allowed in the system anyway. 
This is key part actually. Before this PR, we call escapeDash on all parts, including UUID. Here are sample docker names we have: k8s--net.c5ba7f0e--cadvisor_-_agent.file--e33f1c39, k8s--net.89cd7c44--php1.etcd--cf63dc05_-_44dd_-_11e4_-_a9a5_-_42010af0a893--91f72663

Without this, we couldn't retrieve above UUID, cadvisor-agent, and update-demo properly.