vboot/ui: implement phone recovery screens

Finish implementing phone recovery screen step 1, and
implement step 2.  (Step 3 is in initramfs.)

BUG=b:146399181
TEST=make clean && make runtests
BRANCH=none

Change-Id: I3b18aa0d6c5ec93cb9b69fec7976db434270db79
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2220820
Commit-Queue: Joel Kitching <kitching@chromium.org>
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
2 files changed