Fixes bugs on mobile with texture scaling + auto max quality texturing
(since that generates mipmaps with blits from an image which was just generated from
compute, making proper barriers very critical).
We're already in GENERAL so probably not worth to transfer to DST just
to do even more transfers due to the silliness of GenerateMip.
I'm planning to rework the whole texture upload thing to be far more
optimal with some kind of TextureUploadManager
Fixes#13987