Vulkan: Fix invalid clamping of ES3 clear stencil values Added 3 new end2end tests Bug: angleproject:5202 Change-Id: I95f9ffd989105f5bd3283676d6fa46e904503369 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2488481 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com>