healthd is class hal

because it serves health 2.0 HAL. This forces it to restart when
hwservicemanager dies.

Bug: 69069765
Test: kill hwservicemanager, lshal shows backup instance

Change-Id: Ib51caa0e718031a0f8797d8af4c2459b4958a62e
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 2b7d11f..a3213cd 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -712,7 +712,7 @@
     shutdown critical
 
 service healthd /system/bin/healthd
-    class core
+    class hal
     critical
     group root system wakelock