Change ART artifact root dir for odsign.

Bug: 165630556
Test: boot
Change-Id: I692f9442859bd2e0118995d53dcd3a682c8f4252
diff --git a/ondevice-signing/odsign_main.cpp b/ondevice-signing/odsign_main.cpp
index efe7d35..2ef9511 100644
--- a/ondevice-signing/odsign_main.cpp
+++ b/ondevice-signing/odsign_main.cpp
@@ -39,7 +39,7 @@
 const std::string kSigningKeyBlob = "/data/misc/odsign/key.blob";
 const std::string kSigningKeyCert = "/data/misc/odsign/key.cert";
 
-const std::string kArtArtifactsDir = "/data/misc/apexdata/com.android.art/system";
+const std::string kArtArtifactsDir = "/data/misc/apexdata/com.android.art/dalvik-cache";
 
 static const char* kOdrefreshPath = "/apex/com.android.art/bin/odrefresh";