AttributionReportingAggregatableValueDictEntry constructor
      
      AttributionReportingAggregatableValueDictEntry({ 
    
    
- required String key,
 - required num value,
 - required UnsignedInt64AsBase10 filteringId,
 
Implementation
AttributionReportingAggregatableValueDictEntry({
  required this.key,
  required this.value,
  required this.filteringId,
});