Revert "Migrate the blkio controller to the v2 cgroup hierarchy"

This reverts commit f99ca8aeb1d20218663911ec3d1ea12b2ee9fd05.

Reason for revert: b/2768906
(cherry picked from https://android-review.googlesource.com/q/commit:d0ce4ca33cd5b1a48a3ef7f8b6da39e5498421c5)
Merged-In: I9ce259a2c96e9f8dd8c7598204c35922b56f7a0a
Change-Id: I9ce259a2c96e9f8dd8c7598204c35922b56f7a0a
3 files changed