74415 Adding hero example (cla: yes, d: api docs, d: examples, documentation, framework, waiting for tree to go green)

74446 Don’t leak exceptions thrown by message channels (a: tests, cla: yes, framework, waiting for tree to go green)

74447 [flutter_tools] experiment with skipping process resolution (cla: yes, tool)

74469 Implement dartPluginClass support for plugins (cla: yes, tool)

74533 Only write the pid-file while listening to SIGUSR signals. (cla: yes, team, tool, waiting for tree to go green)

74592 Allow long press delay duration for LongPressDraggable to be adjustable (cla: yes, framework, waiting for tree to go green)