Ash Status Tray: enable ManagedDeviceUIRedesign feature

Enable the redesign of UI to show more information when device is
managed.

New UI screenshot:
https://screenshot.googleplex.com/OoKao0qUf8O
https://screenshot.googleplex.com/9wiTBpnxxc1

BUG=921267,1076316

Change-Id: I175f07aefc760fcbff7bd200c748350fbaec43bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2316154Reviewed-by: Tim Song <tengs@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Andre Le <leandre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791957}

ash/public/cpp/ash_features.cc

@@ -63,7 +63,7 @@ const base::Feature kHideArcMediaNotifications{
     "HideArcMediaNotifications", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kManagedDeviceUIRedesign{"ManagedDeviceUIRedesign",
-                                             base::FEATURE_DISABLED_BY_DEFAULT};
+                                             base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kMediaSessionNotification{"MediaSessionNotification",
                                               base::FEATURE_ENABLED_BY_DEFAULT};