Update the interactive_flex example for the new event handlers
Update the interactive_flex example for the new event handlers

flutter/flutter,turnidge/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,aghassemi/flutter,tvolkert/flutter,tvolkert/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,aghassemi/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,cbracken/flutter,turnidge/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,turnidge/flutter,cbracken/flutter,flutter/flutter,turnidge/flutter,Hixie/flutter,turnidge/flutter,Hixie/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,aghassemi/flutter,aghassemi/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter