MaterialType Default Values Not Initially Applied

[santorac]

Describe the bug
If you change the default value of a material property in a .materialtype file, that change will not get picked up by .material files of that type.

Steps to reproduce

1. Set AtomSampleViewer as the active project
2. Run the AP
3. Modify MinimalPBR.materialtype by
   a. Set metallic defaultValue to 1
   b. Set roughness defaultValue to 0
4. Note the AP reprocesses MinimalPBR.materialtype but does not reprocess MinimalPBR_Default.material
5. Run AtomSampleViewer
6. Open RPI/Mesh sample
7. Select a model to preview (recommended materialeditor/viewportmodels/shaderball.azmodel)
8. Select the material materials/minimalpbr/minimalpbr_default.azmaterial
9. Note the surface is a rough white surface
10. In the AP window, the Assets page, find MinimalPBR_Default.material
11. Right click -> reprocess file
12. Note in AtomSampleViewer the model is now shiny chrome

Expected behavior
The model should have looked like shiny chrome the first time around.

Actual behavior
You have to manually force the AP to process the material file in order for the appearance to be updated.

Assets required
Use AtomSampleViewer

Found in Branch
https://github.com/o3de/o3de/tree/stabilization/2110

Additional context
As part of an effort to reduce asset processing times when shader are updated, material build dependencies were loosened. They are now too loose, so materials are not reprocessed when they ought to be.

See also #5215
See also #6594

[santorac]

To work around this issue, open the Asset Processor window, "Assets" page, right-click on the folder that has all your .material files, "Reprocess folder".