add sandcastle device type test base discovery (#47119)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/47119
Test Plan:
tests
1. test_cuda still works:
`buck test --no-cache -c test.external_runner=tpx mode/dev-nosan //caffe2/test:cuda -- --use-remote-execution --force-tpx`
2. test_torch is blocked on D24623962
`buck test --no-cache -c test.external_runner=tpx mode/dev-nosan //caffe2/test:torch -- --use-remote-execution --force-tpx`
Reviewed By: mruberry
Differential Revision: D24649868
fbshipit-source-id: 97cb41996ea0c37a66a4bf2154e254d2d2912a17
