Add additional GCC Builds using Docker

Bug: skia:9632
Change-Id: If487a89a5750d6493bca3e841837a0a71b01c554
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/254797
Auto-Submit: Ben Wagner aka dogben <benjaminwagner@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
16 files changed