Windows 10 build 18356.1

Windows 10 version 1903 build 18356 was released on 2019-03-12 to Insiders in the Fast Ring and on 2019-03-15 to Insiders in the Slow Ring.

New changes

 * An early preview of the phone screen feature in the My Phone app has been added.
 * The watermark and timebomb have been removed.
 * The copyright dates in winver have been updated to 2019.
 * Other bugfixes and improvements.