Add sample code to DefaultTextStyleTransition (#64638)
Add sample code to DefaultTextStyleTransition (#64638)


flutter/flutter,flutter/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,cbracken/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,flutter/flutter,cbracken/flutter,cbracken/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,flutter/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,tvolkert/flutter