Update to kernel headers v4.7.2.

Modify the kernel header update script to rename C++ keyword
struct members to something else. This fixes problems when including
these kernel files in C++ code.

Also, make a manual change to linux/fib_rules.h and comment out the
value FRA_PAD since it conflicts with a special android kernel value
FRA_UID_START that has not been upstreamed yet.

Test: Built aosp_angler, aosp_x86_64, aosp_mips (bionic only)
Test: Booted on angler and ran bionic unit tests
Test: Built these changes in internal master

Change-Id: Ia22b7e3ca409404696dba76311f49157f4a9ceed
diff --git a/libc/kernel/uapi/linux/tcp_metrics.h b/libc/kernel/uapi/linux/tcp_metrics.h
index 4bc3e48..6eed74e 100644
--- a/libc/kernel/uapi/linux/tcp_metrics.h
+++ b/libc/kernel/uapi/linux/tcp_metrics.h
@@ -53,17 +53,18 @@
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   TCP_METRICS_ATTR_SADDR_IPV4,
   TCP_METRICS_ATTR_SADDR_IPV6,
+  TCP_METRICS_ATTR_PAD,
   __TCP_METRICS_ATTR_MAX,
-};
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+};
 #define TCP_METRICS_ATTR_MAX (__TCP_METRICS_ATTR_MAX - 1)
 enum {
   TCP_METRICS_CMD_UNSPEC,
-  TCP_METRICS_CMD_GET,
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+  TCP_METRICS_CMD_GET,
   TCP_METRICS_CMD_DEL,
   __TCP_METRICS_CMD_MAX,
 };
-#define TCP_METRICS_CMD_MAX (__TCP_METRICS_CMD_MAX - 1)
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define TCP_METRICS_CMD_MAX (__TCP_METRICS_CMD_MAX - 1)
 #endif