Fix the path to zlib_fingerprint.

This uses the BuildArtifacts directory instead of hard-coding the
/data/nativetest path. This fixes the unittests for 64-bits targets.

Bug: None
Test: Ran unittests on 64-bit target
Change-Id: I9ee73542f8cba405f939218b408f40f93385d7ef
diff --git a/payload_consumer/delta_performer_unittest.cc b/payload_consumer/delta_performer_unittest.cc
index 09bbb7c..53e4ed0 100644
--- a/payload_consumer/delta_performer_unittest.cc
+++ b/payload_consumer/delta_performer_unittest.cc
@@ -68,13 +68,6 @@
     "fjoTeLYZpt+WN65Vu7jJ0cQN8e1y+2yka5112wpRf/LLtPgiAjEZnsoYpLUd7CoV"
     "pLRtClp97kN2+tXGNBQqkA==";
 
-#ifdef __ANDROID__
-const char kZlibFingerprintPath[] =
-    "/data/nativetest/update_engine_unittests/zlib_fingerprint";
-#else
-const char kZlibFingerprintPath[] = "/etc/zlib_fingerprint";
-#endif  // __ANDROID__
-
 // Different options that determine what we should fill into the
 // install_plan.metadata_signature to simulate the contents received in the
 // Omaha response.
@@ -906,6 +899,12 @@
 // kCompatibleZlibFingerprint.
 TEST_F(DeltaPerformerTest, ZlibFingerprintMatch) {
   string fingerprint;
+#ifdef __ANDROID__
+  const std::string kZlibFingerprintPath =
+      test_utils::GetBuildArtifactsPath("zlib_fingerprint");
+#else
+  const std::string kZlibFingerprintPath = "/etc/zlib_fingerprint";
+#endif  // __ANDROID__
   EXPECT_TRUE(base::ReadFileToString(base::FilePath(kZlibFingerprintPath),
                                      &fingerprint));
   EXPECT_TRUE(utils::IsZlibCompatible(fingerprint));