Add ability to adjust init log level at runtime.

+ Add a new property, sys.init_log_level, which can be set after init
  bootstrap. This will control the level at which init does prints to klog.

Change-Id: Ia15b2110157b5e6b713785ece9b0fb94889be6c8
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 08b08fe..a2c9c0f 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -428,6 +428,9 @@
 on nonencrypted
     class_start late_start
 
+on property:sys.init_log_level=*
+    loglevel ${sys.init_log_level}
+
 on charger
     class_start charger