Roll Skia from a1a3afe95136 to 568ef84d3f8a (1 revision)

https://skia.googlesource.com/skia.git/+log/a1a3afe95136..568ef84d3f8a

2021-06-04 csmartdalton@google.com Re-enable sk_VertexID support on SwiftShader Vulkan

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://skia-autoroll.corp.goog/r/android-master-autoroll
Please CC nifong@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Test: Presubmit checks will test this change.
Exempt-From-Owner-Approval: The autoroll bot does not require owner approval.
Bug: b/188239650
Bug: b/186777432
Change-Id: I1e8ae76d5c5e3a7a01393a989e8049c2278e7c79