camera: Reduce logspam from VirtualDeviceCameraIdMapper

Any operation involving a binder call with camera clients would go
through the virtual device camera id mapper, so the fetch results
shouldn't log unless enabled.

Test: build

Change-Id: Ia77ecb07f885309b8a80c1100e2dd2cf80e267f9
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>