layers: Add tracking of VkDescriptorUpdateTemplateKHR

Add tracking of the new VkDescriptorUpdateTemplateKHR handle.

Also, update to include proper VUIDs for the corresponding checks
in object_tracker.cpp with help from Mark L and Mike S.

Change-Id: I4a665cfa2e8b4d8faf2a0ebd583c759e399b1599
diff --git a/layers/threading.h b/layers/threading.h
index 20d0297..83b1a44 100644
--- a/layers/threading.h
+++ b/layers/threading.h
@@ -306,8 +306,7 @@
           c_VkDisplayModeKHR("VkDisplayModeKHR", VK_DEBUG_REPORT_OBJECT_TYPE_DISPLAY_MODE_KHR_EXT),
           c_VkSurfaceKHR("VkSurfaceKHR", VK_DEBUG_REPORT_OBJECT_TYPE_SURFACE_KHR_EXT),
           c_VkSwapchainKHR("VkSwapchainKHR", VK_DEBUG_REPORT_OBJECT_TYPE_SWAPCHAIN_KHR_EXT),
-          // TODO: Add proper structure for VkDescriptorUpdateTemplateKHR
-          c_VkDescriptorUpdateTemplateKHR("VkDescriptorUpdateTemplateKHR", VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT)
+          c_VkDescriptorUpdateTemplateKHR("VkDescriptorUpdateTemplateKHR", VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_KHR_EXT)
 #else   // DISTINCT_NONDISPATCHABLE_HANDLES
           c_uint64_t("NON_DISPATCHABLE_HANDLE", VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT)
 #endif  // DISTINCT_NONDISPATCHABLE_HANDLES