Camera: Verify offline session behavior in VTS

Camera offline sessions can be used as way to
free up and share camera resources. Check that
the corresponding HIDL API behaves as per
documentation.

Bug: 135142453
Test: adb shell /system/bin/VtsHalCameraProviderV2_4TargetTest
--hal_service_instance=android.hardware.camera.provider@2.4::ICameraProvider/internal/0

Change-Id: I5b714061894eb2b0179a44dcedf81b0155fb4b54