Make encryption configurable

Add maybeenabledefaultencryption function, that encrypts based
on the encryption flag and appropriate environment variable

Bug: 18764230
Change-Id: Id9a1967d09a7ae63a51240c0a5f3c41505af0e9a
diff --git a/cryptfs.h b/cryptfs.h
index 39ea29a..67592a5 100644
--- a/cryptfs.h
+++ b/cryptfs.h
@@ -218,6 +218,7 @@
   int cryptfs_enable(char *flag, int type, char *passwd, int allow_reboot);
   int cryptfs_changepw(int type, const char *newpw);
   int cryptfs_enable_default(char *flag, int allow_reboot);
+  int cryptfs_maybe_enable_default_crypto();
   int cryptfs_setup_volume(const char *label, int major, int minor,
                            char *crypto_dev_path, unsigned int max_pathlen,
                            int *new_major, int *new_minor);