select current composing region if active when commiting and ensure selection is set when surrounding text changes

src/Android/Avalonia.Android/AndroidInputMethod.cs

@@ -150,6 +150,13 @@ namespace Avalonia.Android
                 _inputConnection.Editable.Replace(diff.index, editableText.Length, diff.diff);
 
                 _inputConnection.EditableWrapper.IgnoreChange = false;
+
+                if(diff.index == 0)
+                {
+                    var selection = _client.Selection;
+                    _client.Selection = new TextSelection(selection.Start, 0);
+                    _client.Selection = selection;
+                }
             }
 
             (int index, string diff) GetDiff()

src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs

@@ -571,8 +571,15 @@ namespace Avalonia.Android.Platform.SkiaPlatform
             BeginBatchEdit();
             _commitInProgress = true;
 
+            var composingRegion = _editable.CurrentComposition;
+
             var ret = base.CommitText(text, newCursorPosition);
 
+            if(composingRegion.Start != -1)
+            {
+                InputMethod.Client.Selection = composingRegion;
+            }
+
             var committedText = text.SubSequence(0, text.Length());
 
             if (_inputMethod.IsActive)