Remove change to event time when sending delayed events in ScreenMagnifier.

This was originally introduced in change id
Idd8539ffed7ba4892c5a916bd34910fd2ef50f75 to fix an issue with touch event
handling in TouchExplorer.  The original issue has been fixed, so this
workaround is no longer needed.

b/24470877

Change-Id: Ie2a782b162b837e9bdc4904a486ed292989f83d8