Pass last touch event to DragDownHelper when starting doze

This stops QS container being stuck in a bad state if it was
being opened over keyguard when dozing started.

Bug: 279707140
Test: manually verified QQS over keyguard to doze transition
Change-Id: Ic8b02151ff5e497993bc9d74fd0db9f9bfe2f8df
1 file changed