Virtual Camera: VDM side implementation

Creates the API and infrastructure to create a VirtualCamera from VDM.

This CL contains the AIDL to enable the communication from client to
system-server and from system-servier to the future
VirtualCameraService

The CL also adds a TestRule for server tests creating VirtualDevices

Test: com.android.companion.virtual.VirtualCameraTest
Bug: 270352264
Change-Id: I581e2d4bb4f0acd3b0fb0d31609c41ffb8fea570