diff --git a/services/core/java/com/android/server/pm/InstantAppRegistry.java b/services/core/java/com/android/server/pm/InstantAppRegistry.java
index 06f67cd..8b9af7a 100644
--- a/services/core/java/com/android/server/pm/InstantAppRegistry.java
+++ b/services/core/java/com/android/server/pm/InstantAppRegistry.java
@@ -38,7 +38,6 @@
 import android.provider.Settings;
 import android.util.ArrayMap;
 import android.util.AtomicFile;
-import android.util.ByteStringUtils;
 import android.util.PackageUtils;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -52,6 +51,7 @@
 import com.android.internal.util.XmlUtils;
 
 import libcore.io.IoUtils;
+import libcore.util.HexEncoding;
 
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
@@ -66,7 +66,6 @@
 import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Locale;
 import java.util.Set;
 import java.util.function.Predicate;
 
@@ -234,7 +233,7 @@
                                                 @UserIdInt int userId) {
         byte[] randomBytes = new byte[8];
         new SecureRandom().nextBytes(randomBytes);
-        String id = ByteStringUtils.toHexString(randomBytes).toLowerCase(Locale.US);
+        String id = HexEncoding.encodeToString(randomBytes, false /* upperCase */);
         File appDir = getInstantApplicationDir(packageName, userId);
         if (!appDir.exists() && !appDir.mkdirs()) {
             Slog.e(LOG_TAG, "Cannot create instant app cookie directory");