GeoJSON source issues with viz updates

[rjimenezda]

How to reproduce:

1. Create a Visualization that uses a GeoJSON source, add a ramp on a property. It should work.
2. Blend to a new Viz that uses a different property for the color ramp, the ramp will assign the same values to all the elements.

I've noticed that if you specify that second property on the first Viz, the ramp will work fine. I'm guessing VL only keeps the minimum GeoJSON properties it requires, so if you have the property the second update requires, everything works fine.

Here's a codepen that shows the issue, uncomment the variable on the Viz string and everything will work as expected: https://codepen.io/rjimenezda/pen/RwbGbYN

[VictorVelarde]

Please @CartoDB/rt-managers can you add this one?

[ramiroaznar]

I have encountered the same issue with filters here.