UPSTREAM: modem-helpers-mbim: allow optional outputs in mm_signal_from_mbim_signal_state()

(cherry-picked from commit d95114a576adbe56e0611e8c1f0b2908d274c52c)

Fixes 470dff235c70683928ab0eb39c64151a8a4ceb7c

BUG=b:278719383,b:278719394
TEST=shill and modemmanager tests
TEST=signal quality indications are reported correctly.

Change-Id: Ia0c7919123ff5487790640e593b42f5f18e48971
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/modemmanager-next/+/4548766
Reviewed-by: Aleksander Morgado <aleksandermj@google.com>
Commit-Queue: Nagi Marupaka <nmarupaka@google.com>
Reviewed-by: Madhav <madhavadas@google.com>
Tested-by: Nagi Marupaka <nmarupaka@google.com>
1 file changed