DeviceAsWebcam is a new service that turns an android device into a
webcam. It requires access to all services that a
regular app needs access to, and it requires read/write permission to
/dev/video* nodes which is how the linux kernel mounts the UVC gadget.
Bug: 242344221
Bug: 242344229
Test: Manually tested that the service can access all the nodes it
needs, and no selinux exceptions are reported for the service
when running.
Change-Id: I45c5df105f5b0c31dd6a733f50eb764479d18e9f
