HarmonyOS 输入法键盘显隐监听问题：sendKeyboardStatus

在对输入法，软键盘状态进行监听时，sendKeyboardStatus。发现点击键盘自带的下拉按键，导致inputMethodController.on("sendKeyboardStatus"）这个监听丢失，不再有显示、隐藏的回调。

复现步骤：（运行下面的示例代码）

1、正常情况：”点击显示输入法键盘“按钮，唤起键盘，toast键盘显示；”点击隐藏输入法键盘“按钮，toast键盘隐藏。可以重复点击多少，每次都有监听回调，没有问题。

2、异常情况：”点击显示输入法键盘“按钮，唤起键盘，toast键盘显示；点击键盘自带的下拉按键（键盘表情旁边的下拉箭头），toast键盘隐藏。之后无论再怎么点击显示或隐藏键盘，都没有toast提示了。疑似sendKeyboardStatus监听被off掉了。请问该如何处理并解决这个问题？或者有没有其他方式监听键盘的显示和隐藏状态。

示例代码如下：

import { inputMethod } from '@kit.IMEKit';
import { promptAction } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';

@Entry
@Component
struct TextInputPage {
  @State isShow: boolean = false;
  inputMethodController = inputMethod.getController();

  aboutToAppear(): void {
    let textConfig: inputMethod.TextConfig = {
      inputAttribute: {
        textInputType: 0,
        enterKeyType: 1
      }
    };
    this.inputMethodController.attach(false, textConfig, (err: BusinessError) => {
      if (err) {
        console.error(`Failed to attach: ${JSON.stringify(err)}`);
        return;
      }
      console.log('Succeeded in attaching the inputMethod.');

      this.inputMethodController.on("sendKeyboardStatus", (keyboardStatus: inputMethod.KeyboardStatus) => {
        if (keyboardStatus === inputMethod.KeyboardStatus.HIDE) {
          console.log('inputMethod.KeyboardStatus.HIDE.');
          promptAction.showToast({ message: "键盘隐藏" })
        } else if (keyboardStatus === inputMethod.KeyboardStatus.SHOW) {
          console.log('inputMethod.KeyboardStatus.SHOW.');
          promptAction.showToast({ message: "键盘显示" })
        }
      })
    });
  }

  build() {
    Stack({ alignContent: Alignment.Bottom }) {
      RelativeContainer() {
        Button("点击隐藏输入法键盘")
          .id('text')
          .alignRules({
            left: { anchor: '__container__', align: HorizontalAlign.Start },
            right: { anchor: '__container__', align: HorizontalAlign.End },
            top: { anchor: '__container__', align: VerticalAlign.Top }
          })
          .onClick(() => {
            this.isShow = false
            this.inputMethodController.hideTextInput()
          })

        Button("点击显示输入法键盘")
          .id('btn')
          .alignRules({
            left: { anchor: '__container__', align: HorizontalAlign.Start },
            right: { anchor: '__container__', align: HorizontalAlign.End },
            bottom: { anchor: '__container__', align: VerticalAlign.Bottom }
          })
          .onClick(() => {
            this.isShow = true
            this.inputMethodController.showTextInput()
          })
      }
      .expandSafeArea([SafeAreaType.KEYBOARD])
      .height('100%')
      .width('100%')

      TextInput({ placeholder: "请输入。。。" })
        .id('TextInputPageHelloWorld')
        .fontSize(15)
        .fontWeight(FontWeight.Bold)
        .height('auto')
        .expandSafeArea([SafeAreaType.KEYBOARD], [SafeAreaEdge.TOP])
        .visibility(this.isShow ? Visibility.Visible : Visibility.None)
    }
    .height('100%')
    .width('100%')

  }
}