In this part, “prior established municipal corporation”:
(1) means a municipal corporation subject to Article XI-E of the Maryland Constitution that includes land added to the regional district under Chapter 596 of the Acts of the General Assembly of 1957; and
(2) includes:
(i) Barnesville;
(ii) Brookeville;
(iii) Gaithersburg;
(iv) Laytonsville;
(v) Rockville;
(vi) Poolesville; and
(vii) Washington Grove.