From the GM Order guide (https://www.gmfleetorderguide.com/). Doesn't say specifically if the driver side is convex, but kind of conveys that by stating the passenger is not.
DLN
Mirrors, outside heated power-adjustable, manual folding, (Passenger mirror includes flat glass, not convex) smaller non-trailer mirror, 11.2" (284.73mm) x 7.15" (181.69mm)
1 - Requires (PCV) WT Convenience Package.
2 - Not available with (PQB) Safety Package.