Vulkan: Batch vkUpdateDescriptorSets calls Right now we are making this calls multiple times as we loop through each shader stage. Qualcomm performance validation layer warns about this. This change will aggregate the calls into one call per dispatch. Bug: b/158787299 Change-Id: I48aa3752f708c26ffbca2fb7947cb8bbc0f76dcd Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2243321 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Reviewed-by: Tim Van Patten <timvp@google.com>