Fix gtest include path in aom_integer_test.cc

Change-Id: I15beaeaf46d7c12795a7db369228c14b57a0b258

test/aom_integer_test.cc

diff --git a/test/aom_integer_test.cc b/test/aom_integer_test.cc
index c7bb1a4..11263d5 100644
--- a/test/aom_integer_test.cc
+++ b/test/aom_integer_test.cc
@@ -11,7 +11,7 @@
 #include <stdint.h>
 
 #include "aom/aom_integer.h"
-#include "gtest/gtest.h"
+#include "third_party/googletest/src/googletest/include/gtest/gtest.h"
 
 namespace {
 const uint64_t kMaximumLeb128CodedSize = 8;