"Unknown" preferred network is sent in edit on CustomerSheet, unable to select

[NicholasGWK]

In Android only, it seems like something is up with preferredNetworks.

When adding a Diners club Test card (and occasionally Discover?) card to a US stripe customer, I am able to add successfully. When I try to EDIT the card though, I get errors.

Checking in the stripe developer logs reveals that the update call for Android send "preferredNetwork: unknown", even if I set preferred networks as part of the CustomerSheet initialization.

On iOS, the request succeeds, and the preferred network is absent from the request.

I may be misunderstanding or it's a quirk of the test environment, but I think preferredNetwork should not really be set for US/Canadian cards right? Happy to provide log ids for the specific requests if that's helpful, but here's the request bodies for each:

iOS, works:

{
  "billing_details": {
    "address": {
      "country": "US",
      "postal_code": "90211"
    }
  },
  "card": {
    "exp_month": "1",
    "exp_year": "29"
  }
}```

Android, fails:

{
"billing_details": {
"address": {
"country": "US",
"postal_code": "90211"
}
},
"card": {
"exp_month": "1",
"exp_year": "2029",
"networks": {
"preferred": "unknown"
}
}
}```

In both cases I was attempting to update the postal code in some trivial way (90210->90211 etc)

Thanks!