Merge "libprocessgroup: Prevent error spam when tests disable all cpus in a...

Merge "libprocessgroup: Prevent error spam when tests disable all cpus in a cpuset" am: 43293def am: 54a3db2f am: 006c39b1 am: 79ee7bf9

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1818662

Change-Id: I13a3e93950e80eb7411aeb35c5e91d3de7eaabdd