Section 108E. Notwithstanding the provisions of any general or special law to the contrary, the minimum annual compensation of each regular police officer of the police department of any city or town shall be not less than the following:
For the first year of service four thousand eight hundred and eighty dollars.
For the second year of service five thousand and thirty dollars.
For the third and each succeeding year of service five thousand five hundred dollars.
This section shall become effective when accepted in a city having a plan E charter by the affirmative vote of a majority of all the members of the city council, and, in the case of other cities by vote of the city council, subject to the provisions of the charter, and in a town by majority vote at an annual town meeting.