If the extensions is exposed, but the backend doesn't support binary
formats, then the part of the tests loading and storing a binary shader
are skipped. With that also Capture/Replay of the test is fixed.

Bug: angleproject:6112
Change-Id: Iaa25860a9be69207e4dbd6213cf77e75fd87a766
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2993090
Commit-Queue: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>