[DU09-3]Modify the NetworkStatsCollection Builder API

1. Adding the bucketDuration with unit as bucketDurationmillis
2. make the Key class be final
3. The Key set parameter be marked with an IntDef

Bug: 220153505
Test: atest NetworkStatsCollectionTest
Change-Id: I8919ed595c2d339e8a5c0fc163b3c40edb4a2ad8
diff --git a/framework-t/api/module-lib-current.txt b/framework-t/api/module-lib-current.txt
index 59ca730..aaaa628 100644
--- a/framework-t/api/module-lib-current.txt
+++ b/framework-t/api/module-lib-current.txt
@@ -90,7 +90,7 @@
     method @NonNull public android.net.NetworkStatsCollection build();
   }
 
-  public static class NetworkStatsCollection.Key {
+  public static final class NetworkStatsCollection.Key {
     ctor public NetworkStatsCollection.Key(@NonNull java.util.Set<android.net.NetworkIdentity>, int, int, int);
   }