enable heap randomization.

Bug: 5250555

Change-Id: I7acb0645402611875c481aec33ece85fced7a336
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 10c0f12..af4967e 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -64,6 +64,7 @@
     write /proc/sys/kernel/sched_wakeup_granularity_ns 2000000
     write /proc/sys/kernel/sched_compat_yield 1
     write /proc/sys/kernel/sched_child_runs_first 0
+    write /proc/sys/kernel/randomize_va_space 2
 
 # Create cgroup mount points for process groups
     mkdir /dev/cpuctl