Prevent exception from being serialized in ErrorInfo

The wrong @Decorator was put in the wrong place to mark the throwable fieldd as transient, now this is fixed and the exception is not serialized. So if a non-serializable throwable is passed, that's not an issue, since it's not going to be serialized. The need for EnsureExceptionSerializable is also gone.

app/src/main/java/org/schabi/newpipe/local/subscription/SubscriptionsImportFragment.java

@@ -90,8 +90,7 @@ public class SubscriptionsImportFragment extends BaseFragment {
                     new ErrorInfo(new String[]{}, UserAction.SUBSCRIPTION_IMPORT_EXPORT,
                             NewPipe.getNameOfService(currentServiceId),
                             "Service does not support importing subscriptions",
-                            R.string.general_error,
-                            null));
+                            R.string.general_error));
             activity.finish();
         }
     }