third-party.gni: Search includes using -I.

This will ensure that the headers from the dependencies will have
precedent over system headers, thus preventing situations where system
headers will block dependency headers and prevent compilation.

Change-Id: I0d480a6d3898f2da99cf2706c5335aaac05b4e4d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/220276
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/AUTHORS b/AUTHORS
index 9e5856c..192d69c 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -40,6 +40,7 @@
 Samsung <*@samsung.com>
 Samsung Open Source Group <*@osg.samsung.com>
 Sergey Melnikov <Melnikov.Sergey.V@gmail.com>
+Shachar Langbeheim <nihohit@gmail.com>
 Skia <*@skia.org>
 Skia Buildbots <skia.buildbots@gmail.com>
 Sony Mobile Communications Inc. <*@sonymobile.com>