HarmonyOS TextInput/TextArea设置.enterKeyType(EnterKeyType.Send)后，键盘自动收起问题

TextInput相关api不支持TextArea，在onSubmit回调中调用event.keepEditableState()即可。示例参考如下：

@Entry
@Component
struct SoftKeyboardEnterTypeExample {
  controller: RichEditorController = new RichEditorController()

  build() {
    Column() {
      Button("停止编辑").onClick(() => {
        this.controller.stopEditing()
      })
      RichEditor({ controller: this.controller })
        .margin(10)
        .border({ width: 1 })
        .height(200)
        .borderWidth(1)
        .borderColor(Color.Red)
        .width("100%")
        .enterKeyType(EnterKeyType.Send)//.enterKeyType(EnterKeyType.Search)
        .onSubmit((enterKey: EnterKeyType, event: SubmitEvent) => {
          console.log("trigger richeditor onsubmit" + enterKey);
          //this.controller.addTextSpan(" type["+ enterKey +"] triggerred")
          event.keepEditableState();
        })
    }.height("100%").justifyContent(FlexAlign.Center)
  }
}