bionic tests: switch to using android-base/file.h for TemporaryFile

A matching definition of TemporaryFile exists in libbase now.

Test: compile
Bug: 119313545
Change-Id: I6f84dbf3af9a9c4b270a2532a36c9cb4c0f6bb8f
diff --git a/tests/stdio_ext_test.cpp b/tests/stdio_ext_test.cpp
index d4616ef..d84fda0 100644
--- a/tests/stdio_ext_test.cpp
+++ b/tests/stdio_ext_test.cpp
@@ -29,7 +29,8 @@
 #include <wchar.h>
 #include <locale.h>
 
-#include "TemporaryFile.h"
+#include <android-base/file.h>
+
 #include "utils.h"
 
 TEST(stdio_ext, __fbufsize) {