DO NOT MERGE: Revert "Revert "Add libprocessgroup dependency and fix sched_policy include""

This reverts commit 11c2ff5c.

Reason for revert: AOSP is fixed with new vendor image

Change-Id: I96db6ffe9cce3d5158b96c171026839d62ec3756
Signed-off-by: Suren Baghdasaryan <surenb@google.com>