Icon Animations are available in the new Themes and Styles feature.
Contact Sensor devices only report an ‘open’ or ‘closed’ state based on the standard capability definition, but you might be able to use Rules along with Variables to create a special ‘stays open for X minutes’ state like you’re looking for. At that point, we would need something like the Style/Icon State Mapping for Custom Attributes feature request to be implemented to enable you to pick a different style for your custom (variable) state. Feel free to cast a vote on the linked thread if you’re interested in it. 