This will avoid breaking the render pass when clearing depth through
clearWithDraw if the depthClamp Vulkan feature is not present.

Bug: angleproject:4836
Change-Id: I845fd5074dd95f6896da89f9e119ebc5000a5688
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2462719
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>