Disable draw instanced support on virgl.

Bug: b/188410972
Change-Id: Ic2f6daf4b919efa76c8136345e763bfa17bb1050
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/420716
Auto-Submit: Tao Wu <lepton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
3 files changed