28938 Add a flutter create --list-samples command (cla: yes, tool)

28944 fix missing variable name (cla: yes, framework, waiting for tree to go green)

28951 Quick fix for shader warm up (cla: yes, framework)

28953 Include platformViewId in semantics tree (cla: yes, framework, severe: API break)

28955 Add more doc pointing to the EditableText’s rudimentary nature around gesture handling (cla: yes, framework)

28963 Fix for post submit on cirrus (cla: yes)

28970 Fix coverage shard and print summary after test run (cla: yes, waiting for tree to go green)