[ButtonGroup] Implement height change animation in vertical MaterialButtonGroup

[patzly]

Hi all, let me know if I should open an issue first for a pull request like this: I wrote on Mastodon with Liam Spradlin from the design team who helped designing the button groups behavior, my question was whether a vertical button group also should animate the height of the button neighbors like it animates the width in horizontal orientation:

@iamliam Hi Liam, one specific question regarding button groups: in the next expressive update of my metronome app I would like to use vertical button groups of MDC Android with large icon buttons. The view library doesn't animate the height of the buttons on tap as it would animate the width in a horizontal button group and I think there aren't any specs for vertical button groups in the docs. Should the height also be animated or are vertical button groups generally not intended?

@patzly the height should be animated in both orientations, because the design intent is to affect the surrounding buttons on interaction. If it's not supported, I can pass that along to the team working on the library!

I found no open or closed issue for that so I implemented it on my own, I hope it's all correct! Tests are green and the catalog button group animations are working now in vertical orientation like Liam said.

[patzly]

@pekingme Just wanted to kindly ask if this might make it into the next alpha? :)