Uncomment string/bytes fields in oneof nano.

javanano/src/test/java/com/google/protobuf/nano/unittest_nano.proto

@@ -171,8 +171,8 @@ message TestAllTypesNano {
   oneof oneof_field {
     uint32 oneof_uint32 = 111;
     NestedMessage oneof_nested_message = 112;
-    // string oneof_string = 123;
-    // bytes oneof_bytes = 124;
+    string oneof_string = 123;
+    bytes oneof_bytes = 124;
     fixed64 oneof_fixed64 = 115;
   }
 }