Specular Isn't Affected for Materials Set to the Eye Shader If r.IrisNormal is Enabled

Specular Doesn't Affect a Material with the Eye Shader If r.IrisNormal is enabled.

Found in 4.22 CL# 7053642, 4.23 CL# 8115738, 4.24 CL# 8302014

1. Download and Create a 4.22 Digital Human Sample Project
2. Open the Project
3. Open the material instance M_EyeRefractiveMike_L_Inst or M_EyeRefractiveMike_R_Inst
4. Try to Change the Specular for the Iris or Scelera

Results:
The specularity for both doesn't change at all unless you go to the defaultengine.ini for the project and change it to 0

Expected:
The specularity would function as expected