Update support checks for descriptorIndexing/drawIndirectCount

Update support checks for descriptorIndexing/drawIndirectCount

Use core feature struct for checks in Vulkan 1.2 context and
extension feature struct for previous API versions.

Affects:
dEQP-VK.descriptor_indexing.*
dEQP-VK.binding_model.descriptorset_random*
dEQP-VK.draw.indirect_draw.*

Components: Vulkan

Change-Id: I07ca69a5d0e7c38523c2f06e8769fa38228e0b38