gvisor-containerd-shim moved. It now has a stable URL that run_tests.sh always
uses.
PiperOrigin-RevId: 223188822
Change-Id: I5687c78289404da27becd8d5949371e580fdb360
More tests will come, but it's worth getting what's done so far reviewed.
PiperOrigin-RevId: 219734531
Change-Id: If15ca6e6855e3d1cc28c83b5f9c3a72cb65b2e59