Refactor removed default test dimension
Refactor removed default test dimension

ptrace was always selected as a dimension before, but not
anymore. Some tests were specifying "overlay" expecting that
to be in addition to the default.

PiperOrigin-RevId: 332004111

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor