add external/libnfnetlink

Bug: 34666705
diff --git a/default.xml b/default.xml
index 688264d..afa2a1c 100644
--- a/default.xml
+++ b/default.xml
@@ -214,6 +214,7 @@
   <project path="external/libmojo" name="platform/external/libmojo" groups="pdk" />
   <project path="external/libmpeg2" name="platform/external/libmpeg2" groups="pdk" />
   <project path="external/libmtp" name="platform/external/libmtp" groups="pdk" />
+  <project path="external/libnfnetlink" name="platform/external/libnfnetlink" />
   <project path="external/libnl" name="platform/external/libnl" groups="pdk" />
   <project path="external/libogg" name="platform/external/libogg" groups="pdk" />
   <project path="external/libopus" name="platform/external/libopus" groups="pdk" />