Fixes from sample count change

Re blacklist imagination msaa on Vulkan and fix i->1 bug in GL

Bug: skia:
Change-Id: I8045565b2064d2ee037ab43b167e6d5d3a59268e
Reviewed-on: https://skia-review.googlesource.com/24780
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
3 files changed