A bill filed by Gov. Charlie Baker to overhaul the beleaguered Massachusetts Bay Transportation Authority is the subject of a second public hearing this week.Baker filed the bill after Boston's record-setting snowfall of more than 9 feet last winter caused widespread delays and shutdowns of MBTA service.Baker named an advisory panel to study the transit system and then used their recommendations to file a bill with state lawmakers.Baker has already wrested control of the state Department of Transportation board and won the backing of the state Senate and House Speaker Robert DeLeo for a separate financial control board to oversee management of the T.The Legislature's Transportation Committee questioned members of the advisory panel at an earlier Statehouse hearing.The follow-up hearing is scheduled for 6 p.m. Wednesday at Tufts University.