vboot/ui: use trusted keypress in cancel TO_DEV test

In order to ensure that the TO_DEV action function does not
trigger TO_DEV confirmation for the PHYSICAL_PRESENCE_KEYBOARD=1
case, use trusted DOWN and ENTER keys to navigate and press the
"Cancel" button.  If this is erroneously picked up by the TO_DEV
action function, then a transition to developer mode will occur.

This hole in test coverage was discovered by CL:2234678.

BUG=b:146399181
TEST=PHYSICAL_PRESENCE_KEYBOARD=0 make runtests
TEST=PHYSICAL_PRESENCE_KEYBOARD=1 make runtests
BRANCH=none

Signed-off-by: Joel Kitching <kitching@google.com>
Change-Id: Id8db074e4e9398a2f7fbfe348059c2c195bc8d90
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2237088
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Tested-by: Joel Kitching <kitching@chromium.org>
Commit-Queue: Yu-Ping Wu <yupingso@chromium.org>
1 file changed