Set minimap Icon sizes to default Dota values.

Set minimap Icon sizes to default Dota values.
- Heroes need to be easily visible, so upped the value to default.
- Creeps, won't be present, but I've kept the value in case I change my
mind later.
- Runes also won't be visibly present for players, only for spectators,
which I'm not sure works? None theless I've changed it to the default
size.