Make sure DragDownHelper is told of CANCEL touch event

In certain cases, the drag down helper will be active but touch
events will immediately cease to it. Make sure that a CANCEL
tell the DragDownHelper so that it can reset state.

Test: atest NotificationShadeWindowViewControllerTest
Fixes: 332575818
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
TEAMFOOD

Change-Id: I23340d7fbc7c22de70e464b81e714afc301add64