hidl_test: move duplicated code to shared lib

Test: hidl_test

Change-Id: Ia68b78d44d68a6b254c686afe64faf7cc89510d7
diff --git a/tests/foo/1.0/default/FooCallback.cpp b/tests/foo/1.0/default/FooCallback.cpp
index d3eef77..e4704f2 100644
--- a/tests/foo/1.0/default/FooCallback.cpp
+++ b/tests/foo/1.0/default/FooCallback.cpp
@@ -3,7 +3,9 @@
 
 #include "FooCallback.h"
 #include <android-base/logging.h>
+#include <hidl-test/FooHelper.h>
 #include <inttypes.h>
+#include <utils/Timers.h>
 
 namespace android {
 namespace hardware {