(a) This chapter may not be construed to affect:
(1) the terms of an agreement authorized by Chapter 174 between the county and county employees; or
(2) any provision of a civil service statute applicable to a county employee.
(b) If an agreement authorized by Chapter 174 or a civil service statute applicable to a county employee conflicts with this chapter or an ethics code adopted or enforced under this chapter, the agreement or civil service statute prevails.