After we enabled
PIE_MULTISELECT_AND_COMMA_IN_ALLOWED_VALUES
, all <+input>.allowedValues(...) become multiple selection
Please add support of multiple selection and single selection inputs int the same pipeline.
Requirement: when one pipeline contains input variables
  1. <+input>.allowedValues(aa,bb,cc)
  2. <+input>.allowedValues(11,22,33)
want to implement #1 multiple selection, #2 single selection