26227 Give integration tests unique temp folder names (a: tests, cla: yes)

26235 rev the min dart sdk dep in the templates to 2.1.0 (cla: yes, tool)

26238 Remove long-deprecated TwoLevelList (cla: yes, f: material design, framework, severe: API break)

26239 Force DatePicker value to stay within firstDate and lastDate upon year change (cla: yes, f: date/time picker, framework)

26244 move analysis_options to package (cla: yes, team)

26246 Teach drag start behaviors to DragGestureRecognizer (cla: yes, f: gestures, f: scrolling, framework)

26249 Revert “Replace netls and netaddr with dev_finder” (cla: yes, tool, ○ platform-fuchsia)