Adds a checkout command to annotated_run.py

To ease the transition into our new adt-infra branch, we will use the
annotated run script to accomplish this for us on our bots.  Any bot on
the master ('old') branch will move to the new emu-master-dev branch
once a new build is kicked off.

Change-Id: I3130d97db7d2318091d8656ff8d6958c512df27b
1 file changed