suggestion in the process of data format convert

[Alisa742]

In the process of converting av2 to metadrive format, there is a problem of transferring the test data and I get the mistake outputs as follows:

there is no problem in converting validation data, so I think maybe it is the discrepancy between val data and test data. However it is wrong.
In order to solve the problem, I read the scenarionet/convertor/argoverse2/utils.py, and found:

so I made some alterations, there is no mistakes in converting test data of av2.

[QuanyiLi]

Thank you for the feedback! Could you file a PR to fix this?