Automatic merge from submit-queue
Make CPU constraint for l7-lb-controller in density test scale with #nodes
Just noticed that we changed the memory last time, but didn't change cpu. From the last run:
```
Sep 13 04:25:03.360: INFO: Unexpected error occurred: Container l7-lb-controller-v0.9.6-gce-scale-cluster-master/l7-lb-controller is using 0.642709233/0.15 CPU
```