63940 Add sample code to RelativePositionedTransition (a: animation, cla: yes, d: api docs, d: examples, documentation, framework, waiting for tree to go green)

63969 Revert “Roll Engine from 7571e7c380fd to b300be3df32b (60 revisions)” (cla: yes, engine)

63972 Revert “Remove TODOs added for HTTP abort() change in dart sdk” (a: tests, cla: yes, framework, tool)

63974 Move away from deprecated NoSuchMethodError to NoSuchMethodError.withInvocation (cla: yes, framework, waiting for tree to go green)

63976 [flutter_tools] trim trailing newline from vm service logging events (cla: yes, tool, waiting for tree to go green)