DO NOT MERGE New ext4enc kernel switching from xattrs to ioctl

(cherry-picked from commit 9f53fb4abca1ee3af7b537c95445161db4b81f86)

This is one of three changes to enable this functionality:
  https://android-review.googlesource.com/#/c/146259/
  https://android-review.googlesource.com/#/c/146264/
  https://android-review.googlesource.com/#/c/146265/

Bug: 18151196

Change-Id: I05b96f49b8848e82484a500e4536bdb4d2cdd635
3 files changed