detachables: Fix language menu size in recovery

BUG=b:35585623
BRANCH=None
TEST=Reboot into recovery, scroll to language menu
     and make sure that you can scroll and select
     other languages.

Change-Id: I6fe7f0550b05e33eaeef928cd23932f5a40fe9ad
Signed-off-by: Shelley Chen <shchen@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/544897
Reviewed-by: Randall Spangler <rspangler@chromium.org>