[FEA] Allow writing to `/var/run`

[jacobtomlinson]

Is your feature request related to a problem? Please describe.
When running jobs on NGC Base Command Platform the NGC Jobs runtime attempts to create a directory called /var/run/mnrun to create a PID file. Since the RAPIDS container has switched from root to rapids this path is no longer writable and BCP jobs fail to do this.

Describe the solution you'd like
Create /var/run/mnrun in our image as root and chown it to rapids.

Describe alternatives you've considered
Make /var/run writable by the rapids user. However this is not a recommended linux practice.