Fix windows and android errors

crates/eframe/src/native/run.rs

@@ -1858,8 +1858,8 @@ mod wgpu_integration {
         #[cfg(target_os = "android")]
         fn drop_window(&mut self) -> std::result::Result<(), egui_wgpu::WgpuError> {
             if let Some(running) = &mut self.running {
-                running.windows.remove(&0);
-                pollster::block_on(running.painter.set_window(None))?;
+                running.windows.write().remove(&ViewportId::MAIN);
+                pollster::block_on(running.painter.write().set_window(ViewportId::MAIN, None))?;
             }
             Ok(())
         }

crates/egui-winit/src/lib.rs

@@ -1124,7 +1124,7 @@ pub fn create_winit_window_builder(builder: &ViewportBuilder) -> winit::window::
     }
 
     #[cfg(target_os = "windows")]
-    if let Some(drag_and_drop) = builder.drag_and_drop {
+    if let Some(enable) = builder.drag_and_drop {
         use winit::platform::windows::WindowBuilderExtWindows as _;
         window_builder = window_builder.with_drag_and_drop(enable);
     }