Capture/Replay: Fix default uniform matrix capture We were only reading back a single location, rather than multiple locations required for arrayed types. Test: Angry Birds 2 MEC Bug: b/157672184 Change-Id: I8029dc5ece3b9dbff7c3c84c188996e622362767 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2231804 Commit-Queue: Cody Northrop <cnorthrop@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>