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

This reverts commit f99ca8aeb1d20218663911ec3d1ea12b2ee9fd05.

Reason for revert: b/2768906

Change-Id: I9ce259a2c96e9f8dd8c7598204c35922b56f7a0a
diff --git a/rootdir/init.rc b/rootdir/init.rc
index fb64736..317f809 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -219,6 +219,26 @@
     write /dev/stune/nnapi-hal/schedtune.boost 1
     write /dev/stune/nnapi-hal/schedtune.prefer_idle 1
 
+    # Create blkio group and apply initial settings.
+    # This feature needs kernel to support it, and the
+    # device's init.rc must actually set the correct values.
+    mkdir /dev/blkio/background
+    chown system system /dev/blkio
+    chown system system /dev/blkio/background
+    chown system system /dev/blkio/tasks
+    chown system system /dev/blkio/background/tasks
+    chown system system /dev/blkio/cgroup.procs
+    chown system system /dev/blkio/background/cgroup.procs
+    chmod 0664 /dev/blkio/tasks
+    chmod 0664 /dev/blkio/background/tasks
+    chmod 0664 /dev/blkio/cgroup.procs
+    chmod 0664 /dev/blkio/background/cgroup.procs
+    write /dev/blkio/blkio.weight 1000
+    write /dev/blkio/background/blkio.weight 200
+    write /dev/blkio/background/blkio.bfq.weight 10
+    write /dev/blkio/blkio.group_idle 0
+    write /dev/blkio/background/blkio.group_idle 0
+
     restorecon_recursive /mnt
 
     mount configfs none /config nodev noexec nosuid