29532 Reland composite physical layers on all platforms (cla: yes, customer: dream (g3), customer: fuchsia, framework)

29540 Improve Navigator documentation (cla: yes)

29563 Avoid flickering while dragging to select text (cla: yes, f: material design, framework)

29564 Update progress indicator API docs (cla: yes, f: material design, framework)

29566 Manually roll engine to 5088735e5f (a: tests, cla: yes, framework)

29568 make build runner configurable (cla: yes, team)

29572 DropdownButton Icon customizability (cla: yes, f: material design, framework)

29604 added friendlier error for invalid AndroidManifest.xml (cla: yes, tool, ▣ platform-android)