GitLab

It appears that GetCharacteristicsAsync() will implicitly open a GATT
service for exclusive access. We don't want this so this change adds an
explicit OpenAsync() call to choose shared access. The test fakes are
updated to only support shared access.

Bug: 968816
Change-Id: I30af95fe428fad075ae8cbddd3075979a834e65f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637192Reviewed-by: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665005}