Make init.updatable_crashing a read/write property

This property will need to be reset during userspace reboot, so it can't
be a read-only property anymore.

Test: builds
Bug: 135984674
Change-Id: I7499849a5809e5d6f17e3ce88ac88dba7147094e
diff --git a/disaster_recovery/flags_health_check.rc b/disaster_recovery/flags_health_check.rc
index 365fd3b..0bede55 100644
--- a/disaster_recovery/flags_health_check.rc
+++ b/disaster_recovery/flags_health_check.rc
@@ -7,5 +7,5 @@
 on property:sys.boot_completed=1
     setprop persist.device_config.attempted_boot_count 0
 
-on property:ro.init.updatable_crashing=1
+on property:sys.init.updatable_crashing=1
     exec - system system -- /system/bin/flags_health_check UPDATABLE_CRASHING