libct/cgroupv1: fix TestGetCgroupMounts test cases
libct/cgroupv1: fix TestGetCgroupMounts test cases

When testing GetCgroupMounts, the map data is supposed to be obtained
from /proc/self/cgroup, but since we're mocking things, we provide
our own map.

Unfortunately, not all controllers existing in mountinfos were listed.
Also, "name=systemd" needs special handling, so add it.

The controllers added were:

 * for fedoraMountinfo case: name=systemd
 * for systemdMountinfo case: name=systemd, net_prio
 * for bedrockMountinfo case: name=systemd, net_prio, pids

Signed-off-by: Kir Kolyshkin <3a017b8ddb3f9cf3e4a59978b004111bdeb97f08@gmail.com>

dqminh/runc,dqminh/runc,estesp/runc,estesp/runc,rhatdan/runc,mikebrow/runc,kolyshkin/runc,xiaochenshen/runc,rhatdan/runc,opencontainers/runc,xiaochenshen/runc,kolyshkin/runc,opencontainers/runc,dqminh/runc,rhatdan/runc,rhatdan/runc,mikebrow/runc,estesp/runc,dqminh/runc,opencontainers/runc,kolyshkin/runc,kolyshkin/runc,xiaochenshen/runc,opencontainers/runc,mikebrow/runc