Turn on xt_bpf module in userspace

The kernel will use xt_bpf module to collect per interface stats instead
of using xt_qtaguid in future. Turn on the userspace part of xt_bpf so
the related iptable rules and operations can be successfull.

Test: iptables -t raw -I bw_raw_PREROUTING -m bpf --object-pinned /sys/fs/bpf/xtbpf_prog
      It should not return error about bpf header not find.
Bug: 72111305

Change-Id: Ic08d73c990e3237478aae97fe2a702f272816265
(clean cherry picked from aosp commit
 2b00efe0f8147b53b13908519d1b3405009d6ac0)
diff --git a/config.h b/config.h
index 45a1adf..7bff59c 100644
--- a/config.h
+++ b/config.h
@@ -85,3 +85,6 @@
 
 /* Location of the iptables lock file */
 #define XT_LOCK_NAME "/system/etc/xtables.lock"
+
+/* Define to 1 if you have the <linux/bpf.h> header file. */
+#define HAVE_LINUX_BPF_H 1