Renaming Parameters resets all Instances in Level and Thumbnails

Renaming a Parameter in a Base Material will make all instances of that Base Material in the level and the instance's thumbnail reset to default values from Base Material until the Instance is opened in the editor.

Also Reproduced in Main Promotable-CL-2513846 and Launcher 4.7.5

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==Original Report==
Currently in Materials or Material Functions if you have created a Parameter and assigned a value for that Parameter in a Material Instance and choose to rename the parameter, the Material Instances all lose their assigned values and you must go through and reset them. If we could do something like a Get Set in the Material Instances so those associations are updated in the event of a rename.

Also Reproduced in 4.7 P5 and Main Promotable-CL-2425512

TL;DR Repro Steps:

1. Open attached 'MI_Reset_Test' Project
2. Open 'M_Base' Material
3. In 'M_Base' Material, rename 'Texture' Parameter to 'Base_Color'
4. Save 'M_Base'

See Results and Expected Below

FULL Reproduction Steps:

1. Open QAGame Editor
2. Create a New Material called 'M_Base'
3. In 'M_Base', Add a Texture Sample Parameter named 'Texture' into Base Color
4. Assign Texture2D'/Engine/EngineResources/AICON-Green.AICON-Green' to 'Texture'
5. Save Material
6. In the Content Browser, Right Click Material >> Create Material Instance called 'MI_Test'
7. In 'MI_Test', check 'Texture' to True
8. In 'MI_Test', Assign Texture2D'/Engine/EngineResources/AICON-Red.AICON-Red' to 'Texture'
9. Save and Close Material Instance
10. Place a Cube in the Level
11. Assign 'MI_Test' to the Cube
12. Back in 'M_Base', rename the 'Texture' Parameter to 'Base_Color'
13. Save the Material 'M_Base'

RESULTS: The Instances return to using the Green Texture not the Assigned Red Texture (Having the Material Instance open OR opening the Material Instance resets the Instances)

EXPECTED: The Material Instances automatically update without having to reopen OR they should be marked dirty.

Changing Texture Material Parameter Name temporarily forces all instances to use the original texture