[infra] Add MSAN GPU (SwiftShader) bot

Bug: skia:9152
Change-Id: I3f1713a765854a56d709a48e510cbfbff4f191cc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/219522
Commit-Queue: Eric Boren <borenet@google.com>
Reviewed-by: Ravi Mistry <rmistry@google.com>
5 files changed