The provisions of existing laws relative to civil and criminal juries and jury trials in justice courts in townships shall govern in jury trials in which the jury is drawn in accordance with the provisions of this act, unless contrary to the provisions of this act or to the provisions of other laws or charter provisions to which such court is subject: Provided, That the only qualifications necessary to being placed on a jury list and serving as a juror are those stated in section 4 of this act.