Remove FLAG_ACTIVITY_FORWARD_RESULT in 2-pane flow

Settings$CreateShortcutActivity does not necessary to be
displayed in 2-pane and it seems no scenario needs the flag
Intent.FLAG_ACTIVITY_FORWARD_RESULT.

Bug: 241346847
Test: build pass
Change-Id: I7a8fca61b453db70233b151711df516649424e3a