28679 Shader warm-up doc fixes (cla: yes)

28681 Expanded Snippet for API Docs (cla: yes, d: api docs, d: examples)

28683 Remove the old HaTS implementation on API docs (cla: yes, d: api docs)

28684 Add capability to run build_runner tests for tool (cla: yes)

28687 Make shader warm-up async so it can handle image (cla: yes)

28688 Initialize the lifecycle state with initial state in window. Roll engine (19 commits) (cla: yes, customer: mulligan (g3), framework)

28698 Roll engine to 99f3f7a9c246f1ebedc6eefd867cde250b370380 (cla: yes)