Re-enable amber stack trace on Linux with proper timeout killing (#351)
Re-enable amber stack trace on Linux with proper timeout killing (#351)

* Re-enable amber stack trace on Linux with proper timeout killing

* Fix nit

* Fix more nits

google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz