Capture/Replay: Allow disabling program trimming. The ANGLE_CAPTURE_TRIM_ENABLED variable disables program trimming when set to 0. This is useful for trace validation, which expects the GL state vectors to be identical. Bug: angleproject:5133 Change-Id: I3ab41de80af7b223c4cb8a1b7e14f049717305fc Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3193417 Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Cody Northrop <cnorthrop@google.com> Commit-Queue: Jamie Madill <jmadill@chromium.org>