Refactor validation of partial compressed texture uploads Optimized ValidCompressedSubImageSize for valid usage and simplified its control flow. Fixed false negative validation when the replaced image region does not fill the entire level but nevertheless reaches the image boundaries. Updated InternalFormat::getCompressedImageMinBlocks to use IsPVRTC1Format helper function. Fixed InternalFormat::computeCompressedImageSize for 3D compressed texture blocks. Removed redundant checks from ValidateES3TexImageParametersBase. Optimized IsPVRTC1Format helper function to be a constexpr. Adjusted tests, added suppressions for Intel and Adreno. Bug: angleproject:7473 Change-Id: I6fadce949785a35e2706b06eeb00e878aa3710a7 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4037671 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com>