Enable `chromium.resultdb.result_sink` on fyi builders

As found in https://crbug.com/1141606#c5, the symptom appeared on
Windows-10-18363 bots only, but not on Windows-10-17134.

Since 2020-10-21, fyi win builders run tests on Windows-10-17134 bots
only, and it should be safe to enable resultdb on fyi builders.
In the meanwhile, I will continue investigating into the slowness issue.

R=chanli@chromium.org,gbeaty@chromium.org
CC=nodir@chromium.org,bpastene@chromium.org

Bug: 1141606
Change-Id: I48a8ca06724828cd887bc260be71716d8db2ffee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518111Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Scott Lee <ddoman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823708}

infra/config/lib/ci.star

@@ -615,7 +615,7 @@ def fyi_builder(
         # TODO(crbug.com/1108016): Move this kwarg to ci.builder(), after
         # ResultSink and result_adapter is confirmed to work.
         experiments = {
-            "chromium.resultdb.result_sink": 0,
+            "chromium.resultdb.result_sink": 100,
         },
         **kwargs
     )