Issue Summary

Running an Assets Import with Missing objects outbound reference updates the object twice

Steps to Reproduce

1. Create an Object Type (say Parent Organization), create two attributes (say Name and Child).
2. Create an object for this Object Type with both attributes as "Switch  
3. Create another Object Type (say Child Organization), add an attribute called Parent, which is of Type Object and Type Value "Parent Organization"  - thereby creating a reference
4. Create an import like below with CSV follwing
   

1. Run the Import, this will create 2 Objects
2. For Parent2, mark Child as None and again add it.
3. Update the CSV to remove the 2nd entry, and run the import again

Expected Results

There should be 4 activities shown for Parent2 

Updated Child2 -> None
Updated None -> Child2 
Updated Child2 -> None
Created Object

in this particular order only. 

Actual Results

 But when the relationship is not found and it updates the object, the timestamp is not updated and it shows previous timestamp and therefore the order is not correct. 

Detailed loom video: https://transfer.atlassian.com/preview/9031834/attachment/268b8ed2-31f3-4c2a-a79b-83f3ede4cddc