camera: Register CameraHalDispatcher to Mojo Service Manager

Currently CameraHalDispatcher is shared between Chrome browser process
and Cros Camera Service by mojo. However, the connection is established
by socket. Now there is Mojo Service Manager, this CL registers
CameraHalDispatcher to Mojo Service Manager and still left the legacy
socket. Once Cros Camera Service is migrated to Mojo Service Manager,
there should be a CL to cleanup the socket related function.

BUG=b:258095854
Test: Manually by tast -verbose run camera.HAL3*.

Change-Id: I79d01530e2653ebd5f6d49aaabc7034192323c45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4462778
Commit-Queue: Sean Li <seannli@google.com>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Wei Lee <wtlee@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1157004}