Enable Smart Text Selection feature by default

Launch bug: https://crbug.com/850610

Bug: b/32781610
Change-Id: I0982bf19511e1ff16543998e3845e119af3b46ea
Reviewed-on: https://chromium-review.googlesource.com/c/1157279Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Commit-Queue: David Jacobo <djacobo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605916}

components/arc/arc_features.cc

@@ -52,7 +52,7 @@ const base::Feature kNativeBridgeExperimentFeature {
 // When enabled, the context menu will show contextual quick actions based on
 // the current text selection.
 const base::Feature kSmartTextSelectionFeature{
-    "ArcSmartTextSelection", base::FEATURE_DISABLED_BY_DEFAULT};
+    "ArcSmartTextSelection", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Controls ARC USB host integration.
 // When enabled, Android apps will be able to use usb host features.