Merge "Revert "Migrate the blkio controller to the v2 cgroup hierarchy"" am: 921d266c

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2049926



Change-Id: Iab5a3987158f0e856e9acfab76f0cee28d67f173
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>