TF-32 Add domain layer of download attachment for android platform

core/lib/domain/exceptions/download_file_exception.dart

@@ -0,0 +1,31 @@
+import 'package:equatable/equatable.dart';
+
+abstract class DownloadFileException with EquatableMixin implements Exception {
+  final String message;
+
+  DownloadFileException(this.message);
+
+  @override
+  String toString() => message;
+
+  @override
+  List<Object> get props => [message];
+}
+
+class CommonDownloadFileException extends DownloadFileException {
+  CommonDownloadFileException(message) : super(message);
+
+  @override
+  List<Object> get props => [message];
+}
+
+class CancelDownloadFileException extends DownloadFileException {
+  CancelDownloadFileException(cancelMessage) : super(cancelMessage);
+
+  @override
+  List<Object> get props => [message];
+}
+
+class DeviceNotSupportedException extends DownloadFileException {
+  DeviceNotSupportedException() : super('This device is not supported, please try on Android or iOS');
+}