camera: Add more VTS tests for ICameraProvider@2.6

Add initial test exercising getConcurrentStreamingCameraIds() and
isConcurrentSessionConfigurationSupported()

Bug : 148180006

Test: VtsHalCameraProviderV2_4TargetTest --gtest_filter=PerInstance/CameraHidlTest.configureConc*
      on cuttlefish

Change-Id: If3821ba5452d487e9a0d83d01e2da86ddf509b50
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>