add daemon.log to the daemon spec (#31273)
add daemon.log to the daemon spec (#31273)

* add daemon.log to the daemon spec

* mention use in flutter run --machine

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