animationEnabled arg ignored by BasicDropdownContent component

[tzellman]

This is occurring in v3.0.1, possibly others, but the only version I am locally using/testing.

When dealing with an issue related to #540 I was hoping to get around the error by disabling animation.

According to the published docs, BasicDropdownContent supports an animationEnabled arg, however it appears that the code is not using the arg in the animationEnabled getter.

Is this intentional and the docs are outdated (i.e. 2.x)? Or should a user be able to specify:

<dd.Content @animationEnabled={{false}} >

I can follow-up this issue with a PR. ❤️