rewriteActiveSurvey method
Need to rewrite the entire survey structure for property to be persisted.
Implementation
void rewriteActiveSurvey(bool actionTaken, int shownCount) {
assert(activeSurvey != null);
properties[activeSurvey!] = {
_surveyActionTaken: actionTaken,
_surveyShownCount: shownCount,
};
}