“Registering material null at index 0 inside a RenderMeshArray failed.” Warning thrown when entering Play mode in “MinimalVehicleScene” in HDRP Template

Steps to reproduce:
1. Create new Unity project using High Definition 3D Template
2. Open Package Manager, install com.unity.vehicles and com.unity.entities.graphics package and import Samples
3. In Project window navigate to Assets > Samples > Vehicles > 0.1.0-exp.5 > Minimal Vehicles Sample > Scenes and open MinimalVehicleScene.unity scene
4. Enter Play mode and observe the Console window

Actual results: Warnings - Registering material null at index 0 inside a RenderMeshArray failed - is thrown in the Console
Expected results: No warnings are thrown in the Console

Reproducible with versions:  0.1.0-exp.5 (6000.2.0b1)

Tested on (OS): MacBook Pro, 2021 (M1), Sequoia 15.4.1