Refactor USB permission handling and reset initial channel sync flag

android/app/src/main/kotlin/com/meshcore/meshcore_open/MeshcoreUsbFunctions.kt

@@ -82,13 +82,6 @@ class MeshcoreUsbFunctions(
                     return
                 }
 
-                val granted =
-                    intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)
-                if (!granted) {
-                    result.error("usb_permission_denied", "USB permission denied", null)
-                    return
-                }
-
                 val device = findUsbDevice(portName)
                 if (device == null) {
                     result.error(
@@ -99,6 +92,13 @@ class MeshcoreUsbFunctions(
                     return
                 }
 
+                val granted =
+                    intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)
+                if (!granted || !usbManager.hasPermission(device)) {
+                    result.error("usb_permission_denied", "USB permission denied", null)
+                    return
+                }
+
                 openUsbDevice(device, pendingConnectBaudRate, result)
             }
         }

lib/connector/meshcore_connector.dart

@@ -1169,7 +1169,6 @@ class MeshCoreConnector extends ChangeNotifier {
     _pendingInitialContactsSync = false;
     _bleInitialSyncStarted = false;
     _pendingDeferredChannelSyncAfterContacts = false;
-    _webInitialHandshakeRequestSent = false;
   }
 
   bool get _shouldAutoReconnect =>
@@ -2241,6 +2240,7 @@ class MeshCoreConnector extends ChangeNotifier {
             (_activeTransport == MeshCoreTransportType.bluetooth ||
                 _activeTransport == MeshCoreTransportType.usb)) {
           _pendingDeferredChannelSyncAfterContacts = false;
+          _pendingInitialChannelSync = false;
           unawaited(getChannels());
         }
         break;