Fix more sampleShading issues in dEQP-VK.pipeline.multisample_shader_builtin.*

Fix more sampleShading issues in dEQP-VK.pipeline.multisample_shader_builtin.*

The `pattern` case here does not require per-sample shading, and the
request for the feature is easily disabled. The `write` case could
potentially also run without per-sample shading, but is plumbed
differently, so I have not adjusted it to run per-pixel.

All remaining cases which used per-sample shading have been
adjusted to check for the sampleShading feature efore running.

VK-GL-CTS Issue: 1807
Affects: dEQP-VK.pipeline.multisample_shader_builtin.sample_mask.*
Components: Vulkan

Change-Id: Iab86205fa89ace6f55ad00ba3fc51e2745a28744