Vulkan: Fix EXT_texture_buffer support condition More formats than necessary where required to have the STORAGE_TEXEL_BUFFER feature. This was based on the table in the EXT_texture_buffer spec, but that only applies to sampler buffers. Support for image buffer formats is based on acceptable formats to glBindImageTexture. Bug: b/206367167 Change-Id: I0c94c3d5a99c1e99ee1f9b05b1accdfaa38101af Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3658000 Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Hailin Zhang <hailinzhang@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>