fix: allow initial snapPoint index greater than 0

[BethThomas141]

Motivation

This is to fix bug #1689. Since version 4.5.0 there has been logic that if the container layout is not ready, the returned snapPoints are an array with just a single item [-999]. As a result, on initial load, before the container layout is ready, if you have passed in the index prop to the BottomSheet with a value greater than 0 (e.g. if you're passing in more than one snap point value, and have passed in index={1} as you want the drawer to start open), it immediately errors as the index is out of range of the initial snapPoint array of [-999].

This PR reverts the initial load logic to how it was before version 4.5.0, where if the container layout is not yet ready, it returns instead an array filled with -999 that matches the length of the passed in snapPoint array.

[mlazari]

Any plans on merging this fix? I had to apply a patch with this fix since I was experiencing the same error.