Mark public method as final to fix API lint error.

Bug: 228200518
Bug: 288280751
Test: TH
Change-Id: I33d60ca54c657b1e096b936b9989324114631460
diff --git a/framework/java/android/app/ondevicepersonalization/IsolatedComputationService.java b/framework/java/android/app/ondevicepersonalization/IsolatedComputationService.java
index 8ceefb3..356a75e 100644
--- a/framework/java/android/app/ondevicepersonalization/IsolatedComputationService.java
+++ b/framework/java/android/app/ondevicepersonalization/IsolatedComputationService.java
@@ -115,7 +115,7 @@
      *
      * @hide
      */
-    @Nullable public UserData getUserData(
+    @Nullable public final UserData getUserData(
             @NonNull RequestToken requestToken) {
         return requestToken.getUserData();
     }