Notify to not delay the update of UI

- updateDependentQuestionnaireResponseItems can evaluate
  X-FHIR-Query expression which can delay the update of UI
  for 1-2 seconds depending on the retrieved resource size.
- In the case of clicking next page after selecting an
  answer that shows the next pages based on skip logic
  (tapping this and that very quickly). We notify the UI
  pages immediately, then once the X-FHIR-Query expression
  is processed (1-2 seconds), we notify the UI again.
  Without this changes, when the user taps next page, the
  next pages that is supposed to be shown by skip logic
  will be shown late enough that the user don't see it,
  but if the user taps previous page button, user will see
  the shown pages decided by skip logic. And that looks
  like a bug.

datacapture/src/main/java/com/google/android/fhir/datacapture/QuestionnaireViewModel.kt

@@ -334,6 +334,7 @@ internal class QuestionnaireViewModel(application: Application, state: SavedStat
         questionnaireResponseItem.addNestedItemsToAnswer(questionnaireItem)
       }
       modifiedQuestionnaireResponseItemSet.add(questionnaireResponseItem)
+      modificationCount.update { it + 1 }
 
       viewModelScope.launch(Dispatchers.IO) {
         updateDependentQuestionnaireResponseItems(questionnaireItem, questionnaireResponseItem)