Load the persistent properties after decrypting the /data partition

Fix for bug 3415286.  The persistent properties are normally read early
in the boot process after /data is mounted.  However, for an encrypted
system, at that point /data is a tmpfs ramdisk.  This change adds a new
command to init (load_persist_props) to read the persistent properties,
and adds an action to init.rc to load the persistent properties.  This
action is triggered by setting a property in vold, but that's in a
different CL.

Change-Id: I74b3057974ee6029c29d956b76fef5566700d471
diff --git a/init/init_parser.c b/init/init_parser.c
index 0898ae8..e8e65ac 100644
--- a/init/init_parser.c
+++ b/init/init_parser.c
@@ -113,6 +113,7 @@
         break;
     case 'l':
         if (!strcmp(s, "oglevel")) return K_loglevel;
+        if (!strcmp(s, "oad_persist_props")) return K_load_persist_props;
         break;
     case 'm':
         if (!strcmp(s, "kdir")) return K_mkdir;