camera2: reduce logspam from cameraIdHasConcurrentStreams.

Physical camera ids aren't included in concurrent camera combinations.
The logs aren't real errors. Make them debug logs.

Bug: 184194887

Test: atest LogicalCameraTest#testBasicPhysicalStreaming doesn't show
      unecessary logs while calling getCameraCharacteristics for
      physical camera ids.

Change-Id: I4f6e9030f23c31e0dc796882e6e82964d5a80668
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>