Infrastructure to securely allow only one prompt at boot when encrypted

Add a call to vold that says if we decrypted the data partition. Reset the
flag so that it only returns true the first time.

Bug: 12990752
Change-Id: Ib00be87137c00fb8ad29205c85a3ea187764b702
diff --git a/cryptfs.h b/cryptfs.h
index caa7617..ac678dc 100644
--- a/cryptfs.h
+++ b/cryptfs.h
@@ -166,6 +166,7 @@
   int cryptfs_setfield(char *fieldname, char *value);
   int cryptfs_mount_default_encrypted(void);
   int cryptfs_get_password_type(void);
+  int cryptfs_just_decrypted(void);
 #ifdef __cplusplus
 }
 #endif