• first_attempt filter takes in true or false as variants.
• But while it is getting applied in the query, it is being converted into a string:
  'true' or 'false'

This works on latest clickhouse versions, but fails on the older clickhouse versions, with the error:

DB::Exception: Cannot convert string false to type Bool: While processing (first_attempt IN ('false'))

Should fix the issue by converting the way these values are parsed.