Xamarin.Android.Google.BillingClient 8.3.0.2 returns a null ProductDetailsList

### Android framework version

net10.0-android

### Affected platform version

VS 2026, .NET 10

### Description

In my Android .NET MAUI app, I have a subscription. I recently dropped James' InAppBilling plugin and migrated to direct use of Xamarin.Android.Google.BillingClient 8.3.0.2. After that, my app was no longer able to see that subscription and query for its price or initiate a purchase. I tracked that behavior down to the billing client's `QueryProductDetailsAsync` returning OK with a null ProductDetailsList.

I was able to work around the problem by thunking to native Java code that calls `queryProductDetailsAsync` and marshals the results back over JNI. However, I'd really prefer to use the official library. Any chance you could take a look and see why ProductDetailsList is null even with a valid Google Play catalog containing products?

Thanks.

### Steps to Reproduce

1. Call QueryProductDetailsAsync inside a valid Google Play Store app.
2. Observe that ProductDetailsList is null

### Did you find any workaround?

As mentioned, falling back to com.android.billingclient.api in Java works fine.

### Relevant log output

```shell

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