Merge pull request #351 from Unity-Technologies/Branch_FixGBufferDebugPS4

Fixed GBuffer full screen debug pass to use DrawFullScreen instead of blit (blit would not work on PS4 with a shader that use only vertexIDs as input).

Assets/ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

                     using (new Utilities.ProfilingSample("DebugViewMaterialGBuffer", cmd))
                     {
                         // TODO: Bind depth textures
-                        cmd.Blit(null, m_CameraColorBufferRT, m_DebugViewMaterialGBuffer, 0);
+                        Utilities.DrawFullScreen(cmd, m_DebugViewMaterialGBuffer, m_CameraColorBufferRT);
                     }
                 }