Reland "StaticKCM: Enable sending layout name by default."

This is a reland of ad28299e6083b156bda90c3b9ec2b88d7bf9df6e

Chrome PFQ for N devices failed because the original CL was landed before the
interface changes to N branch was rolled.
Relanding because ARC++ NYC 5308787 seems to be rolled https://crbug.com/932185#c14

Original change's description:
> 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/1469808
> Reviewed-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}

TBR=oshima@chromium.org,yhanada@chromium.org

Bug: b:122704772
Change-Id: Ie16f442bbfd934fd66267634320e77f1a52995f5
Reviewed-on: https://chromium-review.googlesource.com/c/1474965
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633011}
1 file changed