Remove hardcoded cgroup v2 path

Replace hardcoded cgroup v2 root path with new libprocessgroup API calls.

Bug: 111307099
Test: adb shell dumpsys netd trafficcontroller

Change-Id: I833f42410508ddb6ed7f50cd2ff5e26b3dedc4a8
Merged-In: I833f42410508ddb6ed7f50cd2ff5e26b3dedc4a8
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
4 files changed