Reactive Forms/FormControl Have Incorrect Values When Using iOS QuickPath/Slide to Type

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 8.2.3
• Cross-platform modules: 8.1.1
• Android Runtime: 8.1.1
• iOS Runtime: 8.2.1
• Plugin(s): iqkeyboardmanager (2.0.0)
• NativeScript-Angular: 12.2.0
• Angular: 12.2.13

Describe the bug
When using swipe to type/QuickPath on an iOS keyboard in a reactive form, the word input with QuickPath temporarily replaces the value of the control with just that word instead of appending to the control's previous value. Another input into the keyboard subsequently returns the value back to the full expected value.

To Reproduce

1. Have a TextField bound to a FormControl with the formControl attribute.
2. Subscribe to the control's valueChanged event and output the value each time the value changes.
3. Start inputting a word into the text field, then add a space, for example, "Test ".
4. Now use QuickPath/slide to type to input another word, like "test" again.
5. The last output you see will be "test" instead of "Test test".
6. Input a space, the output will return to the full value of the control.

Expected behavior
When using slide to type/QuickPath, form controls should retain the full value of those controls and emit those values as usual to valueChanged.

一覧にある QuickPath の手順に従い、Angular FormControl にバインドされた iOS の TextField で問題を再現し、その valueChanged イベントを購読します。TextField の値がフォームコントロールに伝播される箇所を追跡し、スワイプ入力中およびその後のスペースの後に、「Test test」のような完全な値が発行されることを確認します。