When Vulkan Validation layers are enabled, also enable the
validation best practices layer which includes ARM's perfdoc
layer. Initially adding skips for all of the best practices
errors that are triggered so that these can be enabled by default.

Bug: b/156661359
Change-Id: I7eab9710bf9632d07ff6b80375d3ad1789d58f7c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2202634
Commit-Queue: Tobin Ehlis <tobine@google.com>
Reviewed-by: Tobin Ehlis <tobine@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Cody Northrop <cnorthrop@google.com>