* Add max-height to Mini Cart drawer.
By giving the Mini Cart contents a max height with the
-webkit-fill-available property, we can ensure that the browser chrome
is accounted for on mobile devices.
* Add `dvh` and keep `vh` as a fallback for height.
By adding `dvh`, we also account for non-webkit mobile browsers that
have the same hidden button issue.
See
https://github.com/woocommerce/woocommerce-blocks/pull/8351#pullrequestreview-1278867767
Keeping `vh` as a fallback, along with `-webkit-fill-available` gives us
the widest range of support.