If a municipality has already adopted charter provisions that require the preparation of an annual budget covering all municipal expenditures and if the municipality conducts a public hearing on the budget as provided by Section 102.006 and otherwise complies with the provisions of this chapter relating to property tax increases, the charter provisions control. After the budget has been finally prepared and approved, a copy of the budget and the amendments to the budget shall be filed with the county clerk, as required for other budgets under this chapter.