61773 Update framePolicy docs (a: tests, cla: yes, d: api docs, documentation, framework, waiting for tree to go green)

61796 Improved docs for minLines in EditableText (a: text input, cla: yes, d: api docs, documentation, framework, waiting for tree to go green)

61948 Add LayoutBuilder example (cla: yes, d: api docs, d: examples, documentation, framework, waiting for tree to go green)

62083 Update the documentation of GlobalKey to explain why it is expensive (cla: yes, d: api docs, documentation, framework, waiting for tree to go green)

62099 Updated references to the old button classes to the new classes in widgets, services, and rendering packages (cla: yes, d: api docs, d: examples, documentation, f: material design, framework, waiting for tree to go green)