Update snap when snapMode changes

Task-number: QTBUG-32258

Change-Id: Id2120acad06d7cfce988400df0067e2c0f16eb24
Reviewed-by: Alan Alpert <aalpert@blackberry.com>
Fixed typo 'backens'

Change-Id: I65e4492d1bc70e5344c0edc37a7c2f87fe355e62
Reviewed-by: Thorbjørn Lindeijer <bjorn@lindeijer.nl>