[gold] envoy config for flutter-engine
[gold] envoy config for flutter-engine

Bug: skia:9449
Change-Id: I47a4dd76cb97825c0c4774339247319415f9aefb
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/243639
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot