cameraserver: Reduce Camera2ClientBase destructor log confusion.

We log disconnect in CameraService::BasicClient::disconnect() and also
in ~Camera2ClientBase(). Since ~Camera2ClientBase() can often run a few
seconds after BasicClient::disconnect(depending on when we get another
binder call), the disconnect logs from the Camera2ClientBase destructor
can be confusing to look at on quick inspection.

Bug: 235352466

Test: Inspect logs

Change-Id: I3fbaa0bde2c21c3b13d5d86f7691eb49f9eb53a2
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>