Vulkan: Optimize FramebufferVk::getSamples() Cache value of samples during syncState(...) and return this value on subsequent queries Bug: angleproject:386749841 Change-Id: I21fb2221187c7b2159fed1b271da642ba2552348 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6619019 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: mohan maiya <m.maiya@samsung.com>