The charter commission shall submit a proposed unified charter to the legislative body of each municipality. The legislative body shall include the proposed charter in a resolution that is considered in accordance with the procedural requirements provided for charter amendments in §§ 4–303(a) and 4–304 of this title. For purposes of § 4–303(a) of this title, the resolution is considered to embrace only one subject. Each legislative body may: adopt or reject the resolution; or amend the resolution, if the legislative bodies of the other municipalities concur.