Add Pixel3a (sargo) jobs

Change-Id: I9fc907efc12105195d0256e00657091b3e5f20fb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240557
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Auto-Submit: Ben Wagner aka dogben <benjaminwagner@google.com>
6 files changed