MoltenVK does not support imageView2DOn3DImage

[TheSpydog]

The Clear3DSlice example fails when running under MoltenVK, with the validation error:

VUID-VkImageCreateInfo-imageView2DOn3DImage-04459(ERROR / SPEC): msgNum: 1450774512 - Validation Error: [ VUID-VkImageCreateInfo-imageView2DOn3DImage-04459 ] | MessageID = 0x56790ff0 | vkCreateImage(): pCreateInfo (portability error) VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT is not supported. The Vulkan spec states: If the VK_KHR_portability_subset extension is enabled, and VkPhysicalDevicePortabilitySubsetFeaturesKHR::imageView2DOn3DImage is VK_FALSE, flags must not contain VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT (https://vulkan.lunarg.com/doc/view/1.3.268.1/mac/1.3-extensions/vkspec.html#VUID-VkImageCreateInfo-imageView2DOn3DImage-04459)

Enabling the imageView2DOn3DImage portability feature results in this error on startup:

[mvk-error] VK_ERROR_FEATURE_NOT_PRESENT: vkCreateDevice(): Requested physical device feature specified by the 5th flag in VkPhysicalDevicePortabilitySubsetFeaturesKHR is not available on this device.

Is there any workaround we could use for this? It's not a big deal if we can't support this feature on MVK, but it would be nice to find a way to at least fail more gracefully.