Make fingerprint UI available for ash-chrome on linux.

- Implement fake biod database.
- Introduce debug shortcuts to simulate finger scanning
for authorization and enrollment:
   - CTRL-ALT-SHIFT-1 : finger 1
   - CTRL-ALT-SHIFT-2 : finger 2
   - CTRL-ALT-SHIFT-3 : finger 3


Bug: b:274857338
Change-Id: I4c1e8be4371cca4a445c1948e716095d3cc73be4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4363806


Reviewed-by: Yulun Wu <yulunwu@chromium.org>
Commit-Queue: Istvan Nagy <iscsi@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1147402}