Refactor uniform block test cases The patch refactors cases that test a uniform block only containing a large array member, which will be translated to StructuredBuffer on D3D backend. Bug: angleproject:3682 Change-Id: I3170a4c82896ce8895909db87c70b80656300383 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2489482 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>