Use a sudoers file for jenkins sudo rights

This way we can start with the file in place on all single-use
slaves, and then remove the file at the beginning of jobs that
should not be able to sudo (for example, unit test jobs).

Change-Id: I37aabdba89d00b45365126c8f776ae6ef8357c8f
Merge "Use a sudoers file for jenkins sudo rights"