[Android] set dialog to null when dismissed (#6031)

fixes #5945

diff --git a/Xamarin.Forms.Platform.Android/Renderers/PickerRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/PickerRenderer.cs
index 60a6eb8..92bc534 100644 (file)
--- a/Xamarin.Forms.Platform.Android/Renderers/PickerRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/PickerRenderer.cs
@@ -168,6 +168,8 @@ namespace Xamarin.Forms.Platform.Android
                        _dialog.DismissEvent += (sender, args) =>
                        {
                                ElementController?.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, false);
+                               _dialog?.Dispose();
+                               _dialog = null;
                        };
                        _dialog.Show();
                }