Enable ash::features::kReduceDisplayNotifications by default

This change flips the kReduceDisplayNotifications feature flag to
enabled by default.
Notifications warning the user that too
many displays are connected and that resolution has changed will still
be shown regardless of flag position.

Bug: 1008046
Change-Id: I4c3762ed0c17d70a3a86d036ebb6c8ffe6859ec2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1827185
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701221}

ash/public/cpp/ash_features.cc

@@ -59,7 +59,7 @@ const base::Feature kPipRoundedCorners{"PipRoundedCorners",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kReduceDisplayNotifications{
-    "ReduceDisplayNotifications", base::FEATURE_DISABLED_BY_DEFAULT};
+    "ReduceDisplayNotifications", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kSeparateNetworkIcons{"SeparateNetworkIcons",
                                           base::FEATURE_DISABLED_BY_DEFAULT};