TimeMachine quota value is taken as MB, not GB
TimeMachine quota value is indicated in GB in the UI. However, when I set the value to, e.g., 500, the value that gets written to the `plist` file is 524288000.
This causes the macOS TimeMachine client to think that it ONLY has 500 MB to use, and quits the backup process.
Either the UI hint should be changed or the UI should properly translate the user input to the file that needs to be stored in `.com.apple.TimeMachine.quota.plist`.
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">