Flip the AppServiceAsh feature default to enabled

BUG=826982
BUG=989789

Change-Id: I49bd3793bf9fcfc89726fd2f7df690421996e0fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1728411Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683064}

chrome/common/chrome_features.cc

@@ -67,7 +67,7 @@ const base::Feature kAppNotificationStatusMessaging{
 // as AppServiceAsh. Enabling any one of those client-specific feature flags
 // also implicitly enables AppServiceServer.
 const base::Feature kAppServiceAsh{"AppServiceAsh",
-                                   base::FEATURE_DISABLED_BY_DEFAULT};
+                                   base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kAppServiceServer{"AppServiceServer",
                                       base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // !defined(OS_ANDROID)