You can prioritize the notification in the app settings. If you change it to normal, it won't get forced to the top and then you can collapse it as normal.
We don't control expand/collapse state directly.
One Jellybean 4.1.1, you must use a two-finger drag down to change the notification size.
On 4.1.2, you should be able to use one finger.
You can select whether to use the Rich Notification or the old-style notification for those who do not wish to use the larger notification.
From the menu tap “Settings” then select “Notifications.”
You can turn the rich notification off by unchecking the “Rich notification” checkbox.
To modify notification priority, tap the “Notification Priority” item.