Camera: Defer physical characteristics map initialization

Querying the camera characteristics of all physical devices
belonging to a logical camera can be expensive when done during
each open camera request.
Defer the physical characteristics map query only for the cases
where it is actually required.

Bug: 335010214
Test: Camera CTS
Change-Id: I66d229b116919c4e966f5fe5a4c6e552991528e3