Add support for boolean fields which may have a 0 value

[juampynr]

_createapi__helper__filter__property() has the following logic to add a filter condition:

 $param_value = (isset($query_params[$param])) ? $query_params[$param] : FALSE;

if ($param_value) {
   $param_value_split = explode(',', $param_value);

If the field you are filtering to is a checkbox whose possible values are 0 or 1 and if you filter by value = 0, the above if statement ill fail and your filter won't be added. We should strictly check that the value is FALSE.