colorShader and colorShaderOccQuery kept after serialize

[Evgeni_Popov]

The two shaders used by the bounding box renderer are not flagged as doNotSerialize. If you don’t want to serialize them, you can set doNotSerialize=true:

Babylon.js Playground

[EDIT] You’re right, though, that we should not serialize them in the first place, so here’s the PR:

Don't serialize internal shader materials