am 3e458241: process: Add setProcessGroup() hidden API call to set the cgroup of a process and all its child threads.

Merge commit '3e458241d9930465a20a861ecb42744355d48e48'

* commit '3e458241d9930465a20a861ecb42744355d48e48':
  process: Add setProcessGroup() hidden API call to set the cgroup of