Catch CalledProcessError for get_last_green_commit
Catch CalledProcessError for get_last_green_commit

Change-Id: I04651cfcbfc8d4f935e4c1178b4001210f48c022

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration