proto: New servo state SBU_LOW_VOLTAGE.

Will be used when SBU voltage issues effect CR50 detection.

BUG=b:173151794
TEST=None

Change-Id: I1f9165d5eaeb9425a70206cc80f392f2da98cb12
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2542963
Reviewed-by: Xixuan Wu <xixuan@chromium.org>
Commit-Queue: Otabek Kasimov <otabek@google.com>
2 files changed