[experiment] Handle case where CPU stats return 0

This may happen if the container ran on GPU.
6 jobs for cpu_stats_fix in 29 minutes and 26 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #143130
docker
build_linux_27

00:08:48

56.0%
passed #143131
docker
build_linux_36

00:08:48

56.0%
passed #143132
macosx
build_macosx_27

00:06:01

56.0%
passed #143133
macosx
build_macosx_36

00:06:32

56.0%
 
  Docker
passed #143134
docker-build
docker_linux_27

00:20:25

58.0%
passed #143135
docker-build
docker_linux_36

00:20:38

58.0%