Asan_extract: Use sys.powerctl

rc-style powerctl has beem removed. Accordingly, asan_extract now
needs to access sys.powerctl directly.

Bug: 36458146
Test: m && m SANITIZE_TARGET=address SANITIZE_TARGET_SYSTEM=true
Change-Id: Ic65a858962b4b3dd613fdbfa09f93d21425bf892

rootdir/asan_extract.rc

@@ -1,6 +1,3 @@
 # When /data is available, look for /system/asan.tar.gz and potentially extract.
 on post-fs-data
     exec - system system -- /system/bin/asan_extract
-
-on early-boot && property:asan.restore_reboot=1
-    powerctl reboot

rootdir/asan_extract.sh

@@ -92,4 +92,4 @@ echo "$ASAN_TAR_MD5" > $MD5_FILE
 
 log -p i -t asan_install "Signaling init to reboot..."
 
-setprop asan.restore_reboot 1
+setprop sys.powerctl reboot