Fall back to IPv4 in devfs_test.dart (#10196)
Fall back to IPv4 in devfs_test.dart (#10196)

Fixes the broken build in the Chromium bots
Hixie/flutter,turnidge/flutter,turnidge/flutter,turnidge/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,turnidge/flutter,Hixie/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,flutter/flutter,flutter/flutter,turnidge/flutter,cbracken/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,cbracken/flutter