Revert "cros: Disable views login by default"

This reverts commit f9b39463.

Reason for revert: Not meant for m70

Original change's description:
> cros: Disable views login by default
> 
> This CL is targeting only for m69.
> 
> Bug: 869411
> Change-Id: Ie0cf9c8eb0f98b53ac3e7c4fda5585185ce95b9c
> Reviewed-on: https://chromium-review.googlesource.com/1156875
> Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
> Commit-Queue: Jacob Dufault <jdufault@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#579432}

TBR=xiyuan@chromium.org,jdufault@chromium.org

Change-Id: I09b0cb12eb8d6c1e66cc7081fe66009e90be4a92
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 869411
Reviewed-on: https://chromium-review.googlesource.com/1156926Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579448}

ash/public/cpp/ash_features.cc

@@ -48,8 +48,7 @@ const base::Feature kTapVisualizerApp{"TapVisualizerApp",
 const base::Feature kTrilinearFiltering{"TrilinearFiltering",
                                         base::FEATURE_ENABLED_BY_DEFAULT};
 
-const base::Feature kViewsLogin{"ViewsLogin",
-                                base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kViewsLogin{"ViewsLogin", base::FEATURE_ENABLED_BY_DEFAULT};
 
 bool IsDockedMagnifierEnabled() {
   return base::FeatureList::IsEnabled(kDockedMagnifier);