libcutils: remove schedgroup fds [DO NOT MERGE]

After removing bg_non_interactive cgroup, there is only a ROOT cgroup.
This CL removes the no-op trying to set cgroup.
It also removes the attempt to open non-exist bg_non_interactive cgroup.

Bug: 36649832
Test: marlin boosts and cgroup ROOT task looks normal
Change-Id: Idef1dfdaa71fde63c98c73a3d37f65416aa6f2e2
(cherry picked from commit bcb6419fc9ac4c33aa1429092df4428e8e3836df)
1 file changed