Emulation needs to be running when the surface is destroyed, but we want
to pause in onStop. So call the surfaceDestroyed callback, as this
accomplished both.
The source Views don't need the transition name. We could get the name
from the sharedView via getTransitionName, but since the TV
ImageCardView isn't inflated in XML it would be to be manually set.
I'm not sure if that would be any cleaner than this.
called.
The user will get a brief system popup tutorial the first time it's
used, so we don't need to show them the menu every time. Once they
enable it by pulling down, hide again after 3s.