Add code cache tests to libnativebridge.

Bug: 18027433

(cherry picked from commit 59a719c466d33479265a3e9c204c8dc9a8f435f1)

Change-Id: I32bcf3ae0d4569d4d8b88168e6c36ddff70b8f7d
diff --git a/libnativebridge/tests/NativeBridgeTest.h b/libnativebridge/tests/NativeBridgeTest.h
index 73c92f1..6a5c126 100644
--- a/libnativebridge/tests/NativeBridgeTest.h
+++ b/libnativebridge/tests/NativeBridgeTest.h
@@ -23,6 +23,7 @@
 #include <gtest/gtest.h>
 
 constexpr const char* kNativeBridgeLibrary = "libnativebridge-dummy.so";
+constexpr const char* kCodeCache = "./code_cache";
 
 namespace android {