Add traits to BitSet64, not 32.

Change-Id: I3d41bbe47f5b02c610f69fc7824e416436d086b1
diff --git a/include/utils/BitSet.h b/include/utils/BitSet.h
index 1ca75fe..75abe6c 100644
--- a/include/utils/BitSet.h
+++ b/include/utils/BitSet.h
@@ -210,7 +210,7 @@
     }
 };
 
-ANDROID_BASIC_TYPES_TRAITS(BitSet32)
+ANDROID_BASIC_TYPES_TRAITS(BitSet64)
 
 } // namespace android