frecon: add command line option to disable login on terminals

Ramdisk/recovery would like for frecon to provide extra terminals beside
splash screen to display debugging and diagnostic logs but they should not
allow login prompt for security reasons.

BUG=chromium:598480
TEST=from shell, stop ui; killall -9 frecon; frecon --enable-vts --no-login;\
and there should be no login prompt on any terminal

Change-Id: I560f3f348f3bddbb9c12cdf27f893535a6d1c104
Signed-off-by: Dominik Behr <dbehr@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/342775
Reviewed-by: Haixia Shi <hshi@chromium.org>
3 files changed