Even when the vendor logo is turned off it can be briefly seen when the login screen changes from the fadeout state back into normal.
The cause it probably that opacity animator doesn't like it when the 'from' and 'to' opacity values are set outside it.
This patch removes the opacity properties, which makes the logo no longer show up.
There's also a minor fix included - placing the drop shadow sooner in the hierarchy because it should be drawn underneath an object, not in front of it.