Refraction Depth Bias In Material Instances Not Updating to Parent Materials Value

Refraction depth bias in Material Instances will not update to Parent Materials value.

Found in 4.19 CL# 4033788, 4.20 CL# 4233996, and 4.21 CL# 4299102

Expected from user:

1. Refraction Depth Bias should not show a yellow arrow next to it in material instances when its value is the same as that of the parent material.
2. Clicking the yellow arrow next to Refraction Depth Bias in a material instance should reset it to the default value of the parent material.
3. After changing the value of Refraction Depth Bias in material instance and then changing it back to the default value, it should continue to update to match that of the parent material when the default value is changed in the parent material.

1. Create a material with refraction and set the Refraction Depth Bias to something other than 0
2. Create a material instance of the refraction material
3. Open the material instance and the parent material 
4. Change the Refraction Depth Bias value again in the parent material
5. Save the parent material
6. Go back to the material instance

Results:
The Refraction Depth Bias value will not change to reflect the same value in the parent material. 

Expected:
The Refraction Depth Bias value would match the change to the parent material.