* This is needed so that the functional tests can elevate and run renderdoccmd
to register the vulkan layer, if needed.
* At the same time remove the old spammy message and ignore flag - this dates
back to before the UI existed, and that should be the way users run RenderDoc
generally and it has a good UI for walking through layer registration if
needed.
* The command is always available, but will only show up in help if attention is
needed.
* Also fix registering installs on shared drives.
baldurk
42841e23be