[Lock screen media controls] Enable by default

Enable the lock screen media controls by default
since these are shipping in M78.

BUG=965546

Change-Id: I159052753625fe4eb8bf3653bf2c7bdffe09615e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773325Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690893}

ash/public/cpp/ash_features.cc

@@ -30,7 +30,7 @@ const base::Feature kLockScreenHideSensitiveNotificationsSupport{
     base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kLockScreenMediaControls{"LockScreenMediaControls",
-                                             base::FEATURE_DISABLED_BY_DEFAULT};
+                                             base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kHideArcMediaNotifications{
     "HideArcMediaNotifications", base::FEATURE_ENABLED_BY_DEFAULT};