Check the DeviceId for generating DragEvent

After introducing multi-device event stream handling in the Dispatcher,
the drag-and-drop logic was not compatible, leading to unexpected
crashes. This is being fixed here.

Bug: 372165513
Test: atest inputflinger_tests
Flag: EXEMPT bugfix

Change-Id: If5dee9023821a386265651bfdbe9c25d04cd5136
Signed-off-by: Linnan Li <lilinnan@xiaomi.corp-partner.google.com>