Prepare CompressedBackendAllocationTest for new compression formats

Bug: skia:9680
Change-Id: Ia11219dff9880b78903d8e4b73565cfed5ccf9de
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/261185
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
1 file changed