Skip new error UNASSIGNED-CoreValidation-Shader-InputNotProduced
and best practices warning
UNASSIGNED-BestPractices-vkCmdClearAttachments-clear-after-load

Bug: b/156661359
Bug: angleproject:4883
Change-Id: I05bf5cac46c54bfb32fa47ea6d3398bd534450f5
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2323641Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Commit-Queue: Tobin Ehlis <tobine@google.com>