Add an option to skip remounting / as MS_PRIVATE.

Also update the minijail0.1 file.

Bug: 27304928

Change-Id: Id5c03fef3c7906e6fe53bad130d74c895f03f730
diff --git a/libminijail.h b/libminijail.h
index 8bd8b39..49f7786 100644
--- a/libminijail.h
+++ b/libminijail.h
@@ -58,6 +58,11 @@
 void minijail_reset_signal_mask(struct minijail *j);
 void minijail_namespace_vfs(struct minijail *j);
 void minijail_namespace_enter_vfs(struct minijail *j, const char *ns_path);
+/*
+ * This option is *dangerous* as it negates most of the functionality of
+ * minijail_namespace_vfs(). You very likely don't need this.
+ */
+void minijail_skip_remount_private(struct minijail *j);
 void minijail_namespace_ipc(struct minijail *j);
 void minijail_namespace_net(struct minijail *j);
 void minijail_namespace_enter_net(struct minijail *j, const char *ns_path);