Assume the 1st USB device configuration has been selected on Android.

device/usb/usb_device_android.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/usb/usb_device_android.h"
 
 #include "base/android/build_info.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 126 matching lines @@
         Java_ChromeUsbDevice_getInterfaces(env, wrapper);
     jsize count = env->GetArrayLength(interfaces.obj());
     config.interfaces.reserve(count);
     for (jsize i = 0; i < count; ++i) {
       ScopedJavaLocalRef<jobject> interface(
           env, env->GetObjectArrayElement(interfaces.obj(), i));
       config.interfaces.push_back(UsbInterfaceAndroid::Convert(env, interface));
     }
     descriptor_.configurations.push_back(config);
   }
+
+  if (configurations().size() > 0)
+    ActiveConfigurationChanged(configurations()[0].configuration_value);
 }
 
 UsbDeviceAndroid::~UsbDeviceAndroid() {}
 
 void UsbDeviceAndroid::PermissionGranted(bool granted) {
   if (granted)
     Open(base::Bind(&UsbDeviceAndroid::OnDeviceOpenedToReadDescriptors, this));
   else
     CallRequestPermissionCallbacks(granted);
 }
@@ skipping 45 matching lines @@
   if (allowed_origins)
     webusb_allowed_origins_ = std::move(allowed_origins);
   if (landing_page.is_valid())
     webusb_landing_page_ = landing_page;
 
   device_handle->Close();
   CallRequestPermissionCallbacks(true);
 }
 
 }  // namespace device