78658 Add fix for RectangularSliderTrackShape (cla: yes, f: material design, framework, team, waiting for tree to go green)

78663 Remove “unnecessary” imports in packages/flutter/lib. (cla: yes, f: cupertino, f: material design, framework, waiting for tree to go green)

78672 Add fixes for [InputDecoration, InputDecorationTheme] hasFloatingPlaceholder -> floatingLabelBehavior (cla: yes, f: material design, framework, team, waiting for tree to go green)

78731 Add MaterialStateBorderSide.resolveWith (cla: yes, f: material design, framework)

78755 Typo fixes (a: internationalization, a: tests, cla: yes, f: cupertino, f: material design, framework, team, tool)