Clatd changes for move of libipchecksum.

libipchecksum is becoming its own library in
frameworks/libs/net and its include files are no longer under
netutils/. Adjust clatd code accordingly.

Also reorder some include files as suggested by clang-format.

Test: m
Test: atest clatd_test
Test: connects to IPv6-only wifi, testipv4.com shows 10/10
Change-Id: I5e4c73065ce828123aef7e8851227f9bdf444ff9
diff --git a/Android.bp b/Android.bp
index 6df3078..9d2d85e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -66,7 +66,7 @@
         "main.c"
     ],
     static_libs: [
-        "libipchecksum",
+        "libip_checksum",
         "libnl",
     ],
     shared_libs: [
@@ -106,7 +106,7 @@
     ],
     static_libs: [
         "libbase",
-        "libipchecksum",
+        "libip_checksum",
         "libnetd_test_tun_interface",
         "libnl",
     ],