Vulkan: Handle texStorage when base level is set In this scenario, we allow the texStorage call to fully populate the image, then let dirty bits change the vkImage to reflect the base level. Bug: angleproject:3948 Bug: angleproject:3949 Test: dEQP-GLES3.functional.shaders.texture_functions.texturesize.* Change-Id: I1f453653a23b9d1802a374def40c9372ada8822a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1841275 Commit-Queue: Cody Northrop <cnorthrop@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>