Capture/Replay: Limit GL_MAX_IMAGE_UNITS further From testing on the bots, the limit of 8 is required. Also happens to be the most common limit per gpuinfo.org. Test: LEGO MEC Bug: b/161716126 Change-Id: I76447a02c5546bda9085a179b123640d2a93474d Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2552557 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Cody Northrop <cnorthrop@google.com>