Vulkan: Don't allocate ExternalFormatIDs for sampling usecases Update the condition for allocating YUV ExternalFormatIDs to exclude sampling-only usecases. Also, rename "isYuvResolve()" to "isYuvExternalFormat()" to better reflect intent. Bug: angleproject:386749841 Change-Id: I0e4f5b79937ea8ad98b5d00fdc7531b34ffa7e16 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6797965 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: mohan maiya <m.maiya@samsung.com>