init: use frecon to display low battery warning on freon images BUG=chromium:529496 CQ-DEPEND=I8178341e00ba70002c265c4202d0dd0634e8c6b3 TEST=via ssh: powerd_setuid_helper --action=shut_down --shutdown_reason=low-battery Signed-off-by: Dominik Behr <[email protected]> Reviewed-on: https://chromium-review.googlesource.com/335584 (cherry picked from commit a87c8a5a91530bcd5fa2b199abd506e09e3f94d6) Change-Id: I389c2c69e917867137383bdc24334caa13dc3566 Signed-off-by: Dominik Behr <[email protected]> Reviewed-on: https://chromium-review.googlesource.com/338513 Reviewed-by: Dominik Behr <[email protected]> Tested-by: Dominik Behr <[email protected]>