CHROMIUM: config: Add vivi to base config for testing purposes

CHROMIUM: config: Add vivi to base config for testing purposes

vivi is a virtual capture driver that acts like a camera. Add it to the default
build for testing purposes.
Eventually we'd like to have it built for testing images only.

BUG=chromium:223099
TEST=manual build and test

Signed-off-by: Pawel Osciak <posciak@chromium.org>
Change-Id: Ic9b4f95eb10ee609d8e070cb93891164da37f4f4
Reviewed-on: https://gerrit.chromium.org/gerrit/46269
Commit-Queue: Pawel Osciak <posciak@google.com>
Reviewed-by: Pawel Osciak <posciak@google.com>
Tested-by: Pawel Osciak <posciak@google.com>