StaticKCM: Enable sending layout name by default.

This CL enables ExoSendKeyboardLayoutName feature by default. By
enabling this feature, ARC++ will use a keyboard layout name instead of
XKB text configuration sent through wl_keyboard interface.

Design doc: go/arc-static-kcm-converter

TEST=manual
BUG=b:122704772

Change-Id: I2d75ed0a817642ac76ab64592a83a910d3c57734
Reviewed-on: https://chromium-review.googlesource.com/c/1469808Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632114}

components/exo/wayland/zcr_keyboard_configuration.cc

@@ -24,7 +24,7 @@ namespace {
 // Send a keyboard layout name instead of XKB contents.
 // TODO(tetsui): Remove when the change becomes default.
 const base::Feature kSendKeyboardLayoutNameFeature{
-    "ExoSendKeyboardLayoutName", base::FEATURE_DISABLED_BY_DEFAULT};
+    "ExoSendKeyboardLayoutName", base::FEATURE_ENABLED_BY_DEFAULT};
 
 ////////////////////////////////////////////////////////////////////////////////
 // keyboard_device_configuration interface: