[Bluetooth] Present user-friendly string on unknownError while pairing.

Bug: 954347
Change-Id: I36aa7aaef7f907d5529c50aaf618fd6c85f40636
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574486
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652911}
1 file changed