Vulkan: Don't sync pipeline cache if warm up is effective If the pipeline cache is being warmed up at link time, the blobs corresponding to each program is individually retrieved and stored in the blob cache. This should be enabled only on platforms where draw time pipeline creation hits the cache due to said warm up. As a result, there's no need to store the aggregate cache (the one owned by RendererVk) in the blob cache too. Bug: angleproject:5881 Bug: b/215230983 Change-Id: I2da5de835e6667b0b2d5859e6804791671888947 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3727227 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Yuxin Hu <yuxinhu@google.com>