[null-safety] add language version to freeform template (#69043)
[null-safety] add language version to freeform template (#69043)


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