Replace htonl with htobe32.

htonl is supposed to be defined in arpa/inet.h, not endian.h. This code
compiles thanks to non-standard endian.h. Being stricter helps make it
more portable.

It would be possible to switch header files instead of switching
functions, but htobe64 is used elsewhere in the code. There is no
"network" function for 64-bit types. It seems slightly cleaner to be
consistent naming things "big endian" rather than mixing terms.

Bug: 110161494
Change-Id: I9b66b967c587d7c0853631d1fbb12e2e41c7d1b2
diff --git a/gatekeeper.cpp b/gatekeeper.cpp
index 052c4db..1d71684 100644
--- a/gatekeeper.cpp
+++ b/gatekeeper.cpp
@@ -232,7 +232,7 @@
     token->challenge = challenge;
     token->user_id = user_id;
     token->authenticator_id = authenticator_id;
-    token->authenticator_type = htonl(HW_AUTH_PASSWORD);
+    token->authenticator_type = htobe32(HW_AUTH_PASSWORD);
     token->timestamp = htobe64(timestamp);
 
     const uint8_t *auth_token_key = NULL;