update_engine: put update_engine into background sched group am: 0a813e6aac

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1782217

Change-Id: I3345b2e65779d5d3ab323a8bd1444c0e944f01cb
diff --git a/update_engine.rc b/update_engine.rc
index b9f80fc..aa39211 100644
--- a/update_engine.rc
+++ b/update_engine.rc
@@ -2,7 +2,7 @@
     class late_start
     user root
     group root system wakelock inet cache media_rw
-    writepid /dev/cpuset/system-background/tasks /dev/blkio/background/tasks
+    task_profiles ServiceCapacityLow LowIoPriority HighEnergySaving
     disabled
 
 on property:ro.boot.slot_suffix=*