Remove individual 3D slice layout transitions

Remove individual 3D slice layout transitions

For VK_KHR_maintenance1 render to 3D slice tests using
VK_IMAGE_CREATE_2D_ARRAY_COMPATIBILITY_BIT_KHR, layout
transitions from undefined would actually affect all
slices in the complete mip level instead of just those
specified in the image view.  Therefore, don't use
VK_IMAGE_LAYOUT_UNDEFINED when previous subpasses may
have already rendered to the other slices.

Affects: dEQP-VK.pipeline.render_to_image.3d.*

VK-GL-CTS issue: 476
Components: Vulkan

Change-Id: I4faaaf0d849ad89dd68ef643cfe38730221f8f55