NullPointer on toLowerCase but I don't use that method anywhere

I can't comment yet, so I will post this as a possible solution, but this seems like an error on Google's side. Multiple people are reporting this crash on the exact same device with the exact same region. So it seems Google runs your app on a virtual or automated device and then that device crashes. This device seems to be a Nexus 5x with local us-US and API level 23.

Source: https://code.google.com/p/android/issues/detail?id=233549