Presubmit OEM check

Add presubmit check to `repo upload` that checks to see
if any OEM names are present in the CL description.

TEST=presubmit unit tests

Change-Id: I9e83164b2e1e5a0e303f6b8cbc8fa410f540cf58
Tested-by: Jack Neus <>
Commit-Ready: Jack Neus <>
Legacy-Commit-Queue: Commit Bot <>
Reviewed-by: Paul Fagerburg <>
Reviewed-by: Jack Rosenthal <>
Reviewed-by: Nick Crews <>
2 files changed