This might not be valid… Based on the 2018.3 documentation, the keyboardmappings.xml file has been removed and the customization of keyboard shortcuts has been deprecated.
https://docs.uipath.com/studio/v2018.3/docs/keyboard-shortcuts
I don’t see reference to either parts of the statement in the latest documentation
However I do have 2019.10.1 installed with the MSI package, and that file does not exist for me.
The following idea has a comment to indicating plans to address this in a future release are in the works.