add ambient light test godot project

tests/godot_project/default_env.tres

@@ -26,10 +26,10 @@ background_mode = 2
 background_sky = SubResource( 1 )
 background_sky_custom_fov = 0.0
 background_color = Color( 0, 0, 0, 1 )
-background_energy = 0.0
+background_energy = 1.0
 background_canvas_max_layer = 0
 ambient_light_color = Color( 0, 0, 0, 1 )
-ambient_light_energy = 0.0
+ambient_light_energy = 1.0
 ambient_light_sky_contribution = 1.0
 fog_enabled = false
 fog_color = Color( 0.5, 0.6, 0.7, 1 )