jupyter container failed when setup playground with multi-users mode

After #2552 merged, the jupyter container failed as the following message:  

``` text
  Warning  Failed     9m33s      kubelet, minikube  Error: failed to start container "notebook": Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"bash\": executable file not found in $PATH": unknown
```