Function that maps an intent to a choice ID defined in for props.slotValue.
IntentUtils.defaultIntentToValueMapper which converts "AMAZON.YesIntent"
to 'yes' and so on. Generally,
(.+)*<Value>Intent" -> 'value'.
filteredSlotType = 'Maybe'. An utterance of 'U: yes' will be interpreted as an
AMAZON.YesIntent. To ensure that intent can be interpreted as the 'yes' answer to a questionnaire question an intentToChoiceMapper must be defined. The default is sufficient for this case and for most cases that involve intents with conventional naming.